Taxane analogs for the treatment of brain cancer

ABSTRACT

Provided herein are compounds and methods for the treatment of brain cancer in a mammal, wherein the method comprises the administration to the mammal a compound that stabilizes tubulin dimers or microtubles at G2-M interface during mitosis but is not a substrate for MDR protein. In particular, the present application relates to the use of an orally effective abeo-taxane, alone or in combination with temozolomide or bevacizumab, for the treatment of brain cancer.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a division of U.S. patent application Ser.No. 12/859,990, filed Aug. 20, 2010, which is in turn continuation ofU.S. patent application Ser. No. 12/529,122, which in turn is a U.S.national stage entry of International Application No. PCT/US2008/055367,filed Feb. 28, 2008, which in turn claims priority to U.S. ProvisionalApplication No. 60/894,169, filed Mar. 9, 2007 and ProvisionalApplication No. 60/892,235, filed Feb. 28, 2007, all of which are herebyincorporated by reference in their entirety.

There is disclosed the treatment of brain cancer employing a taxanederivative, pharmaceutical compositions suitable for use in thattreatment and a new compound of use in that treatment and to the methodof its preparation.

BACKGROUND TO THE INVENTION

Tubulin is the protein that polymerizes into long chains or filamentsthat form microtubules, hollow fibers that serve as a skeletal systemfor living cells.

Microtubules have the ability to shift through various formations whichis what enables a cell to undergo mitosis or to regulate intracellulartransport. The formation-shifting of microtubules is made possible bythe flexibility of tubulin which is why scientists have sought tounderstand the protein's atomic structure since its discovery in the1950s. Certain anticancer drugs bind to tubulin and cause the protein tolose its flexibility, preventing the cell from dividing.

Regulatory approved tubulin binding agents include the taxane s(including paclitaxel and docetaxel) and the vinca alkaloids (comprisedof three agents, vincristine, vinblastine and vinorelbine). Typicallythese agents are administered intraveneously and are dosed every one tothree weeks due to the adverse reactions suffered by patients, includingneurotoxicity, neutropenia, hypersensitivity, and other harmful sideeffects. Thus, there is a continuing need for a dosing regimen thatallows tubulin binding agents to be administered for longer periods oftime to maximize their anticancer effect. Paclitaxel and docetaxel havebeen shown to have widespread clinical utility in treating tumors;however the clinical decrease in effect over time has limited theusefulness of the drug class. A new taxane-like drug with the capabilityto overcome the resistance of the tumors may have utility in the clinic.

Clinically used taxanes such as paclitaxel and docetaxel have not beenapproved for the treatment of brain cancer. The agents do not penetratethe blood brain barrier and remain in the brain sufficiently for them tobe effective. This is also the case with many other anti-cancermedicaments so that brain tumors have proved particularly refractory tochemotherapy. The lack of residency in the brain, for example ofpaclitaxel, may result from efflux related to the P-gp pump.

The design and development of effective anti-tumor agents for treatmentof patients with malignant neoplasms of the central nervous system havebeen influenced by two major factors: 1) the drugs given at highsystemic levels are generally cytotoxic; and 2) the blood-brain barrier(BBB) provides an anatomic obstruction, limiting access of drugs tothese tumors. Accordingly, it is well known that brain cancers areparticularly difficult to treat. The common forms of cancer in the brainare glioblastoma multiforme (GBM) and anaplastic astrocytoma (AA). Themean survival for patients with GBM is approximately 10 to 12 months,while the median survival for patients with AA is 3 to 4 years. Forpatients with GBM, surgery will prolong their lives only a few months.Most cases where treatment of GBM is by surgery and local irradiationresult in relapse within 2 to 4 cm of the original tumor margins.

One current approach to administering a drug that does not cross the BBBinto the brain is by craniotomy, a process by which a hole is drilled inthe head and the drug administered by either intracerebroventricular(ICV) or intracerebral (IC) injection. With ICV administration, the drugdistributes only as far as the ependymal surface of the ipsilateralventricle and does not penetrate significantly into the brainparenchyma. Therefore, the IVC and IC administration methods reach lessthan 1% of the brain volume, and there are few diseases of the brainthat can be treated by such limited penetration.

In contrast, a transvascular route of drug delivery could treatvirtually 100% of the neurons of the brain. Because every neuron isperfused by its own blood vessel, a drug administered tranvascularly canreach every neuron of the brain after crossing the BBB. However, becausethere is no drug-targeting system that will allow drugs to cross theBBB, the transvascular route of administration is unavailable to thevast majority of drug candidates.

Taxanes are described in the literature including EP 1 228 759; EP 1 285920; EP 1 148 055; WO 01/56564; WO 01/57027; WO 94/10996; FR 2 715 846;U.S. Pat. No. 5,352,806; FR 2 707 293; WO 94/08984; WO 92/09589; WO94/20485; WO 93/21 173; Klein L L, “Synthesis of 9-Dihydrotaxol: a novelbioactive taxane”, Tetrahedron letters, vol. 34, no. 13, 1993, pages2047-2050; Datta A et al, “Synthesis of novel C-9 and C-10 modifiedbioactive taxanes”, Tetrahedron letters, vol. 36, no. 12, 1995, pages1985-1988; Klein L L et al, Journal of Medicinal Chemistry, no. 38,1995, pages 1482-1492; J. Demattei et al, “An efficient synthesis of thetaxane-derived anticancer agent abt-271”, Journal of Organic Chemistry,vol. 66, no. 10, 2001, pages 3330-3337; Gunda I Georg et al, “Thechemistry of the taxane diterpene: stereoselective reductions oftaxanes”, Journal of Organic Chemistry, vol. 63, no. 24, 1998, pages8926-8934.

International Patent Application WO 2005/030150 also discloses a seriesof taxane analogues useful for the treatment of cancer as well asmethods of producing them. As used herein, the terms “taxane,”“taxanes,” “taxane derivatives” or “taxane analogs” and the like,include the diterpenes produced by the plants of the genus Taxus (yews),and may be derived from natural sources, may be preprared syntheticallyor may be obtained from semi-synthetic methods or a combination thereof.Such taxanes include paclitaxel and docetaxel that have a 6-membered Aring, as well as the abeo-taxanes that have a 5-membered A ring, asknown in the art and as disclosed herein. The acid catalyzedrearrangement from the 6 membered A ring (and 8 membered B ring) to the5 membered A ring (and 7 membered B ring) of the abeo taxane has beendescribed for other taxane compounds, for example, in L. O. Zamir et al,Tetrahedron Letters, 40 (1999) 7917-7920, L. O. Zamir et al,Tetrahedron, Vol. 53, No. 47, 15991-16008 (1997), L. O. Zamir et al,Vol. 37, No. 36, 6435-6438 (1996), A. Wahl et al, Tetrahedron, Vol. 48,No. 34, 6965-6974 (1992), G. Appendino et al, J. Chem. Soc, Chem.Commun. 1587-1589 (1993), and G. Samaranayake et al, J. Org. Chem. 1991,56, 5114-5119. The nomenclature used in these publications to name therearranged 5 membered A ring structures has been 11(15−>1) abeo-taxanes.International Patent Application WO 2005/030150 discloses a series oftaxane analogues useful for the treatment of cancer as well as methodsof producing them, but no mention is made that these compounds aresuitable for use in the treatment of cancers of the brain.

Several unique characteristics of both the brain and its particulartypes of neoplastic cells create daunting challenges for the completetreatment and management of brain tumors. Among these are the physicalcharacteristics of the intracranial space; the relative biologicalisolation of the brain from the rest of the body; the relativelyessential and irreplaceable nature of the organ mass; and the uniquenature of brain tumor cells. The intracranial space and physical layoutof the brain create significant obstacles to treatment and recovery. Thebrain is primarily comprised of astrocytes, which make up the majorityof the brain mass, and serve as a scaffold and support for the neurons;neurons, which carry the actual electrical impulses of the nervoussystem; and a minor contingent of other cells, such as insulatingoligodendrocytes that produce myelin. These cell types give rise toprimary brain tumors, including astrocytomas, neuroblastomas,glioblastomas, oligodendrogliomas and the like.

The brain is encased in the rigid shell of the skull, and is cushionedby the cerebrospinal fluid. Because of the relatively small volume ofthe skull cavity, minor changes in the volume of tissue in the brain candramatically increase intracranial pressure, causing damage to theentire organ. Thus, even small tumors can have a profound and adverseaffect on the brain's function. The cramped physical location of thecranium also makes surgery and treatment of the brain a difficult anddelicate procedure. However, because of the dangers of increasedintracranial pressure from the tumor, surgery is often the firststrategy of attack in treating brain tumors.

DESCRIPTION OF THE INVENTION

It has now been found that certain taxanes are able to enter the brainand reside there for sufficiently long to show potential effectiveness.In addition, it has been found that certain compounds are of use in thetreatment of cancers including certain difficult cancers such as braincancers. Without being bound by any theory proposed herein, it isbelieved that these compounds will be those that stabilize tubulindimers or microtubules at the G2-M interface during mitosis but whichare not substrates for MDR protein.

The brain cancer treated may be that of primary origin or may be ametastasis of a systemic cancer (e.g. breast cancer, small cell lungcancer, lymphoma and germ cell cancers). The term “brain cancer” or“brain tumor” refers to any tumor that grows in the brain, including,but not limited to, astrocytoma, craniopharyngioma, glioma, ependymoma,neuroglioma, oligodendroglioma, glioblastoma multiforme, meningioma,medulloblastoma and other primitive neuroectoderma. A particularlysignificant brain cancer or tumor in relation to this invention isglioma. A further particularly significant brain cancer or tumor inrelation to this invention is neuroblastoma. Brain disease furtherrefers to cancers which have metastasized to the brain, i.e. cancerswhere the primary location is outside the brain e.g. the breast,prostate, pancreas, bowel or the like but where a secondary tumor hasdeveloped in the brain. Such metastases are also particularlysignificant in relation to this invention. In one aspect, the compoundis a taxane derivative which is not a substrate for MDR protein.Existing marketed taxanes such as paclitaxel and docetaxel can be asubstrate for MDR (MDR1 gene encodes for P-gp which pumps drugs such aspaclitaxel and docetaxel from cells). Hence such existing marketedtaxanes cannot be used in this invention. Certain compounds have beenfound not to be substrates for MDR protein. This may be associated withtheir effectiveness in the brain.

Accordingly the present invention provides a method of treating braincancer comprising administering to a patient in need thereof a compoundof the formula (1):

The compound may be administered as a mixture of diastereoisomers or asa single diastereoisomer.

A particularly single isomer for use is the compound of the formulaS-(1):

The compound of formula S-(1) has improved activity in comparison to itsdiastereoisomers. The single diastereoisomer of the compound of formulaS-(1) may also be employed. This compound has improved solubility incomparison with its diastereoisomer. If used as a single isomer, thecompound is favorably 95% and preferably 99% optically pure anddesirably essentially free of any other isomers, including R-(1).

A further single isomer for use is the compound of the formula R-(1):

This compound also has improved solubility in comparison with itsdiastereoisomers.

If used as a single isomer, the compound is favorably 95% and preferably99% optically pure and desirably essentially free of any other isomer.The present invention also encompasses the compound of formula R-(1) asa single diastereoisomer having a diasteromeric excess of at least 95%and at least 99%.

Processes

Methods for the preparation of the compound of formula (1) are describedin International Patent Applications WO 2005/030150 and WO 2007/126893,and although the structure as provided above was not provided, theseprocesses may lead to its preparation.

DEFINITIONS

-   CSA: Camphorsulfonic Acid-   DCC: N,N′-Dicyclohexyl-Carbodiimide-   10-DAB III: 10-Deacetylbaccatin III-   DCM: Dichloromethane-   DMAP: Dimethylaminopyridine-   DMF: N,N-Dimethylformamide-   DMSO: Dimethylsulfoxide-   HCl: Gaseous or aqueous hydrochloric acid-   Hr: Hour-   HPLC: High Performance Liquid Chromatography-   IPAc: Isopropyl Acetate-   LCMS: Liquid Chromatography Mass Spectrometry-   MTBE: Methyl t-Butyl Ether-   4-PP: 4-Pyrrolidinopyridine-   TEA: Triethylamine-   TES-Cl: Triethylsilyl Chloride-   THF: Tetrahydrofuran-   TPAP: Tetrapropyl Ammonium Perruthenate

A method for synthesizing the compound of formula (3) is shown belowwith reference to Scheme 1. 10-Deacetylbaccatin III (10-DAB III), whichhas formula (4) as shown in Scheme 1, is a commercially available(Sigma-Aldrich) compound used as an intermediate in the preparation ofvarious taxanes.

In this process, 10-DAB III, formula (4), is first protected at both theC-7 and C-IO positions to form the Cl, ClO di-CBZ derivative of formula(5). 10-Deacetylbaccatin III of formula (4) (50 g, 91. mmol) wasdissolved in THF (2 L, 40 ml/g) by warming to 40° C. in a warm-waterbath. The solution was cooled to −41° C. in a Neslab chiller andbenzylchloroformate (46 mL, 3.2 eq, 294 mmol) was added to the stirredchilled solution followed by further cooling to −44° C. To this solution2.3M hexyl lithium solution (130 mL, 3.3 eq, 303 mmol) was addedgradually over 45 min while maintaining the temperature of the reactionmixture at <−39° C. Stirring was continued in the Neslab for 45 minutesat which time HPLC indicated the reaction had gone to completion. At twohours total reaction time, the reaction was quenched by the addition ofIN HCl (40O mL) and IPAc (1 L) and removal from the Neslab chiller. Thereaction was allowed to stir while warming to 10° C. The layers wereseparated and the IPAc layer was washed sequentially with H₂O (500 mL),saturated NaHCO₃ (200 mL) and H₂O (4×500 mL) and then filtered through asilica gel pad. The filtrate was concentrated until solids started toform. IPAc (850 mL) was added and the mixture was heated to 60° C. todissolve some of the solids. To the warm solution, heptanes (800 mL)were added and the solution was cooled in the refrigerator and filtered.The solids collected by the filtration were washed with heptanes anddried under vacuum at 45° C. to give formula (5).

Next, the compound of formula (5) was coupled with a side chain to formthe compound of formula (7). Here, the side chain of the compound offormula (6), (38 g, 99.6 mmol) was dissolved in toluene to a knownconcentration (0.0952 g/mL). This solution was added to the compound offormula (5) (54.0 g, 66.4 mmol). The solution was heated in a warm-waterbath and DMAP (8.13 g, 66.4 mmol) and DCC (25.3 g, 120 mmol) in toluene(540 mL) were added to the warm reaction mixture. While maintaining thetemperature at about 51° C., the reaction was continually stirred andsampled periodically for HPLC. After 3 hours, additional DCC (13.0 g) intoluene (140 mL) was added. The following morning (25.25 hr), MTBE (450mL) was added and the reaction mixture was filtered through a pad ofsilica gel, washed with MTBE followed by ethyl acetate, and concentratedto give the compound of formula (7) as 61.8 g of an oil.

The compound of formula (7) was then deprotected at both the C7 and ClOpositions to give the compound of formula (8). A solution of THF (300mL) and HCl (22 mL) was added to a solution of the compound of formula(7) (61.8 g, 52.5 mmol) in THF (15 mL/g, 920 mL). The resulting solutionwas flushed with nitrogen. A catalyst (10% Pd/C with 50% water, 99.1 g)was added and the flask was flushed with nitrogen three times and thenwith hydrogen three times. The reaction mixture was stirred vigorouslyunder a hydrogen balloon for 21 hours. At this time the reaction wassampled and HPLC indicated that 38% by area of starting material stillremained. Water (10 mL) was added and stirring continued. Twenty hourslater, HPLC indicated the same amount of starting material stillremaining. The reaction mixture was filtered through celite and washedwith THF. It was then concentrated to remove excess THF; fresh catalyst(101 g) was added and the reaction mixture was placed back underhydrogen as before. After another 24 hours, an intermediate compound wasstill present and still more catalyst (20 g) was added. After anotherhour, HPLC indicated that the reaction was complete. The reactionmixture was filtered through celite and washed through with IPAc. Thecombined filtrate was washed with NH₄Cl solution (500 mL), water (500mL), 5% NaHCO₃ (500 mL), H₂O (300 mL), and brine (300 mL). The organiclayer was dried, filtered, and concentrated to give a foam of thecompound of formula 38 (42.5 g). The compound of formula (8) was thenconverted to the compound of formula (9). Formula (8) (41.4 g, 52.5mmol) was dissolved in DCM (500 mL) at room temperature. In the casethat the impurity was water, Na₂SO₄ was added to the solution, and thesolution was filtered through filter paper into to a 2 L flask. Thesolids were collected and washed with DCM (250 mL) and the washingstransferred into the flask. The flask was covered with a septum and N₂balloon. TEA (35 mL) followed by DMAP (1.28 g) and TES-Cl (−30 mL, 3.5eq) were added to the solution and stirred. Additional TES-Cl (15 mL)and TEA (20 mL) were added, and after 6 hours HPLC indicated thereaction had gone to completion.

The reaction was then quenched by the addition of ethanol (25 mL). Thelayers were separated and the organic layer was washed with saturatedNH₄Cl (−500 mL). The organic layer was dried over Na₂SO₄ andconcentrated. A flash column was packed with silica gel and wet with 8:2heptane/IPAc (1.5 L). The solids were dissolved in 8:2 heptane/IPAc (250mL) and filtered to remove solids that would not dissolve. This solutionwas concentrated to −100 mL and applied to the column. The column waseluted with 8:2 heptane/IPAc and fractions collected. Fractions withproduct were pooled and concentrated to give foam of formula (9) (24.5g).

The compound of formula (9) was then oxidized to form the compound offormula (10). Here, solid Na₂SO₄ was added to a solution of formula (9)(24.5 g, 24.0 mmol) and 4-methyl morpholine N-oxide (10.1 g, 84 mmol) inDCM (340 mL) to assure that the reaction was dry. The mixture wasstirred for 1 hour and then filtered through 24 cm fluted filter paperinto a 2 L 3-neck round bottom flask. The Na₂SO₄ solids were washed withDCM (100 mL) and the washings transferred into the flask. Molecularsieves (6.1 g, 0.15 g/g) were added to the solution and stirring wasbegun. TPAP (1.38 g) was added and the reaction was allowed to stirunder a N₂ blanket. Samples were taken periodically for HPLC. AdditionalTPAP (0.62 g) was added after 2 hours and again (0.8 g) after 15 hours.The reaction mixture was applied to a pad of silica gel (86 g), wet with8:2 heptane/IPAc and eluted with IPAc. The fractions were collected,pooled and concentrated to an oil. 4-Methyl morpholine N-oxide (5.0 g)and DCM (100 mL) were added and stirred. Na₂SO₄ (13 g) was added to themixture and it was filtered through filter paper. The Na₂SO₄ solidsremaining in the filter was washed with DCM (45 mL). Molecular sieves (5g) and TPAP (1.03 g) were added to the solution and after 45 minutes,more TPAP (1.05 g) was added. A pad of silica gel was prepared and wetwith 80:20 Heptane/IP Ac. The reaction mixture was applied to the padand eluted with IPAc. Fractions were collected and those fractionscontaining product were pooled and concentrated to give an oil productof formula (10) (21.8 g).

Next, the compound of formula (10) was reduced to form the compound offormula (1 1). NaBH₄ (365 mg, 6 eq) was added to a stirred solution offormula (10) (1.6 g) in ethanol (19 niL) and methanol (6.5 mL) cooled inan ice-water bath. After 1 hour, the reaction mixture was removed fromthe ice-water bath and at 2 hours, the reaction was sampled for HPLC,which indicated the reaction had gone to completion. The reactionmixture was cooled in an ice-water bath and a solution OfNH₄OAc inmethanol (15 mL) was added followed by the addition of IPAc (50 mL) andH₂O (20 mL). It was mixed and separated. The organic layer was washedwith water (20 mL) and brine (10 mL), a second time with water (15 mL)and brine (10 mL), and then twice with water (2×15 mL). It was driedover Na₂SO₄ and placed in the freezer overnight. The following morning asample was taken for HPLC and the reaction was dried and the organiclayer was concentrated on the rotary evaporator. It was placed in thevacuum oven to give a foam product of formula (11) (1.45 g).

The compound of formula (11) was then acylated to form the compound offormula (12). TEA (5.8 mL, 41.5 mmol), Ac₂O (2.62 mL, 27.7 mmol) andDMAP (724 mg, 5.5 mmol) were added to a solution of formula (11) (14.1g. 13.8 mmol) in DCM (50 mL). The reaction was stirred and sampled forHPLC periodically. After 18.5 hours, additional TEA (1.5 mL) and Ac₂O (1mL) were added. At 19 hours, HPLC indicated the reaction had gone tocompletion. The reaction mixture was diluted with IPAc (300 mL) andpoured into 5% NaHCO₃ (100 ml). It was then stirred, separated, and theorganic layer was washed with water (100 mL), saturated NH₄Cl (2×100mL), water (3×50 mL) and brine (50 mL) and then filtered through Na₂SO₄.The mixture was concentrated to give a foam product of formula (12)(14.6 g).

Next, the compound of formula (12) was converted to the compound offormula (13). A quantity of formula (12) (3.0 g, 2.83 mmol) was weighedinto a 100 mL flask. Next, DCM (24 mL) followed by methanol (6 mL) wereadded to the flask at room temperature. Stirring of the mixture beganunder N₂ and camphorsulfonic acid (CSA) (0.0394 g, 0.17 mmol) was added.After 4 hours LCMS indicated the product had formed. 5% NaHCO₃ (15 mL)was added to the reaction mixture; it was shaken vigorously and thentransferred to a separatory funnel. The reaction flask was rinsed intothe separatory funnel with 5% NaHCO₃ (25 mL) and, thereafter, thereaction mixture was shaken and the layers were separated. The organiclayer was washed with brine, dried over Na₂SO₄, and concentrated. MTBE(3×25 mL) was added and the reaction mixture was concentrated to drynessafter each addition to finally give 3.71 g foam. The foam was dissolvedin MTBE (10 mL) and stirred. Heptane (50 mL) was slowly added to thereaction solution and solids began to form immediately. The solids werevacuum filtered and rinsed with heptane (720 mL). The solids werecollected and dried in a vacuum oven at 40° C. to give the compound offormula (13) (2.18 g).

The compound of formula (13) was then converted to the compound offormula (3). A solution of formula (13) (2.1 g, 2.52 mmol) in DCM (10.5mL) was stirred at room temperature. Next, 3,3-dimethoxy-1-propene (2.03g, 17.7 mmol) followed by CSA (0.035 g, 0.15 mmol) were added to thesolution. After the solution was stirred for 3.5 hours, LCMS indicatedthe reaction had gone to completion. The reaction was diluted with DCM(25 mL) and added to a reparatory funnel with 55 mL 5% NaHCO₃ solution.The layers were separated and the aqueous layer was washed with DCM (25mL). The two organic layers were combined, washed with brine, dried overNa₂SO₄ and concentrated. A flash chromatography column was packed withsilica gel (230^4-00 mesh) and wet with 50:50 MTBE/heptane (1000 mL),The reaction mixture was dissolved in MTBE (10 mL), loaded on the columnand eluted with 50:50 MTBE/heptane. The fractions were collected,pooled, concentrated and dried in a vacuum oven at 50° C. to giveproduct of formula (3).

To a solution of the compound of formula (12) (0.500 g, 0.472 mmol) inmethanol, at −19° C. was added 0.2N HCl (1.2 equiv, 2.83 mL) slowly andstirred. The reaction was quenched by the addition of 5% sodiumbicarbonate solution, after stirring the reaction for about 1 hr. Themixture was diluted with ethyl acetate and partitioned. The organiclayer was washed with water, dried (Na₂SO₄) and rotostripped to providecrude compound of formula (13a). The crude product was purified bynormal phase flash chromatography eluting with 15% ethyl acetate inheptane followed by neat ethyl acetate to provide clean product compoundof formula (13a) (0.235 g).

To a solution of compound of formula (13a) (0.41 g) in DMF(N,N-dimethylformamide) was added acroleindimethyl acetal(3,3-dimethoxy-1-propene, 2 mL) followed by camphorsulfonic acid (O0.1g). The reaction mixture was heated at ˜50° C. and monitoredperiodically by LC-MS analysis for progress of the reaction. Thereaction was judged complete at about 3 hours and quenched by additionof 5% sodium bicarbonate solution. The reaction mixture was diluted withIPAc (isopropyl acetate, 20 mL) and water (20 mL). The mixture wasshaken well and the organic layer partitioned. The aqueous layer wasre-extracted twice with IPAc. The combined IPAc layers were washed withwater and rotostripped to provide the crude product formula (3a) as afoam. A Kromasil column (100A, 50 cm×2.1 cm column) was conditioned with65:35 n-heptane: waMTBE (1% water and 1% acetic acid in methyl-t-butylether). The crude compound of formula (3 a) was loaded as a solution intoluene onto the Kromasil column and eluted with 65:35 n-heptane:waMTBE. The pure fractions containing the product were pooled,neutralized with ˜50 mL of 5% sodium bicarbonate solution. The organiclayer was partitioned and evaporated under reduced pressure and driedovernight in the vacuum oven at 40° C. to provide the pure compound offormula (3a) as a white solid (−57 mg). The product was characterized byHPLC/LC-MS and high field multidimensional NMR spectroscopy.

An alternative method for synthesizing the compound of formula (3) isshown below with reference to Schemes 2 to 4.

As shown, paclitaxel of formula 14 is first protected at the 2′-hydroxylwith a hydroxyl protecting group such as tørt-butyldimethylsilyl(TBDMS). To a 500 mL round bottom flask (RBF) equipped with a magneticstir bar was charged 50.0 g (58.6 mmol) paclitaxel, formula 14, 14.0 g(205 mmol, 3.5 eq.) imidazole, and 26.5 g (176 mmol, 3.0 eq.) TBDMS-Cl.The flask was placed under a nitrogen environment and 350 mL (7 mL/gpaclitaxel) anhydrous N,N-dimethyl formamide (DMF) was charged to theflask. The reaction was stirred at room temperature for twenty hours,then was worked up by diluting the reaction solution in 600 mL isopropylacetate (IPAc) and washing with water until the aqueous wash reached pH7, then with brine. The organic partition was dried over magnesiumsulfate, filtered and then was evaporated to a white foam solid to yield66.9 g (93.0 area percent) of unpurified 2′-0-TBDMS protected compoundof formula 15. Next, the 10-acetyl group is removed using methods knownin the art, such as by hydrazinolysis. To a 1 L RBF equipped with amagnetic stir bar was charged 59.5 g compound 15 and 600 mL (10 mL/g)IPAc. The solution was stirred to dissolve compound 15, then 60 mL (1mL/g) hydrazine hydrate was charged to the flask and the reactionstirred at room temperature for one hour. The reaction was worked up bydiluting the reaction solution in 1.2 L IPAc and washing first withwater, then ammonium chloride solution, then again with water until theaqueous wash was pH 7 and lastly with brine. The organic partition wasdried over magnesium sulfate, filtered and evaporated to 55.8 g ofsolid. The solid was redissolved in 3:1 IPAc (1% water):heptane to aconcentration 0.25 g/mL total dissolved solids (TDS) and purified on aYMC silica column; the column eluent was monitored for UV absorbance.The fractions were pooled based on HPLC analysis and evaporated to yield39.3 g (98.6 area percent) of the 2′-0-TBDMS-10-deacetyl compound offormula 16.

The 7-hydroxyl is further protected with a protecting group such astriethylsilyl (TES). To a 500 mL RBF equipped with a magnetic stir barwas charged 39.3 g (42.5 mmol) compound 16 and 15.6 g (127 mmol, 3 eq.)4,4-dimethylaminopyridine (DMAP). The flask was placed under nitrogenand 390 mL (10 mL/g) anhydrous dichloromethane (DCM) was charged to theflask to dissolve the solids followed by 14 mL (84.9 mmol, 2 eq.)TES-Cl. The reaction was stirred at room temperature for three hours.The reaction was worked up by evaporating the reaction solution toapproximately half its starting volume and diluting it in 300 mL EtOAcand washing with water and dilute HCl solutions until the pH of theaqueous wash was approximately 1, then washing with brine. The organicpartition was dried over magnesium sulfate and evaporated to yield 42.0g (97.7 area percent) of white solid of formula 17.

Next, oxidation of the 10-hydroxyl yields a 9,10-diketo compound. To a 1L RBF equipped with a magnetic stir bar was charged 41.0 g (39.4 mmol)of the compound of formula 17, 2.1 g (5.92 mmol, 0.15 eq.) oftetrapropyl ammonium perruthenate (TPAP), 13.9 g (118 mmol, 3 eq.)N-methylmorpholine-N-oxide (NMO). The flask was placed under nitrogenand 720 mL (−20 mL/g) anhydrous DCM charged to the flask to dissolve thesolids. The reaction was stirred at room temperature for 22 hours. Thereaction was worked up by concentrating the reaction solution to halfits volume and then drying the reaction contents onto 175 g silica gel(EM Sciences 40-63μ). The product containing silica was placed on 30 gof clean silica gel (EM Sciences 40-63μ) and the product eluted from thesilica with 4 L methyl tert-butyl ether (MTBE). The MTBE was evaporatedto yield 37.3 g (93.2 area percent) 2′-O-TBDMS-7-O-TES-9,10-diketocompound of formula 18.

Selective reduction of the 9,10-diketo compound yields the9,10-α,α-hydroxy compound. To a 2 L RBF equipped with a magnetic stirbar was charged 37.3 g (35.9 mmol) protected 9,10-diketo compound offormula 18 and 900 mL (−30 mL/g compound 18) of 3:1 EtOH/MeOH. Thesolution was stirred to dissolve the solids then the flask was placed inan ice/water bath and the solution was stirred for 30 minutes. Then 8.1g (216 mmol, 6 eq.) of sodium borohydride (NaBH₄) was charged to theflask and the reaction stirred in the ice/water bath for five hours. Thereaction was worked up by diluting the reaction solution in 1 L IPAc andwashing with 4×750 mL water, then with 200 mL brine. The organicpartition was dried over magnesium sulfate. The aqueous washes werereextracted with 500 mL IPAc. The organic re-extract solution was washedwith 100 mL brine then dried over magnesium sulfate and combined withthe first organic partition. The IPAc solution was concentrated untilsolids began precipitating out then heptane was added to the solution tocrystallize the product of formula 19. The crystallizing solution wasplaced in a freezer overnight. Three crystallizations were done on thematerial, the first yielded 4.1 g (95.3 area percent) product, thesecond yielded 18.3 g (90.9 area percent) product, and the third yielded2.9 g (81.7 area percent) product. The original work on this reactionemployed flash chromatography to purify the product. However, thecrystallizations that were performed gave similar purity, by HPLC, tothe chromatographed material from earlier work.

To a 25 mL RBF, equipped with a magnetic stir bar and under a nitrogenenvironment, was charged 300 mg (0.288 mmol) of the compound of formula19, (0.720 mmol, 2.5 eq.) acetyl chloride (CH₃COCl), 140 μL (1.01 mmol,3.5 eq.) triethyl amine (TEA), 13 mg (0.086 mmol, 0.3 eq.) 4-PP, and 10mL anhydrous DCM. The reactions were stirred at room temperature for 15+hours; reactions generally ran overnight and were monitored by TLCand/or HPLC in the morning for consumption of starting material. Thereactions were worked up by diluting the reaction solution in 20 mLEtOAc and washing with water until the pH of the water washes wasapproximately 7. The organic solution was then washed with brine anddried over sodium sulfate before evaporating to dryness. The resultingproduct is the compound of formula 20.

When the reagent used is a carboxyl anhydride, an exemplary procedure isas follows. To a 25 mL RBF, equipped with a magnetic stir bar and undera nitrogen environment, was charged 300 mg (0.288 mmol) of the compoundof formula 19, (2.88 mmol, 10 eq.) acid anhydride (CH₃COOCOCH₃), 106 mg(0.864 mmol, 3 eq.) DMAP and 5 mL of anhydrous DCM. The reactions werestirred at room temperature for 15+ hours. The reactions were worked upby adding 5 mL saturated sodium bicarbonate solution to the reactionflask and stirring for 5 minutes. The solution was then transferred to areparatory funnel and organics were extracted with 20 niL EtOAc. Theorganic extract was then washed with saturated sodium bicarbonate andwater until the pH of the water washes was approximately 7. The organicpartition was then washed with brine and dried over sodium sulfatebefore evaporating to dryness.

The compound of formula 20 may be deprotected at the T- and 7-positionsin either a two-step process or a single step. For example, as shown inScheme 3, the 7-O-TES group may be removed from formula 20 to giveformula 21 using acetonitrile (ACN) and aqueous HF.

To a 500 mL teflon bottle equipped with a magnetic stir bar is charged2.50 g (2.40 mmol) of the compound of formula 20 and 100 mL ACN. Thebottle is placed in an ice/water bath and the solution stirred for 30minutes. Next, 0.8 mL of 48% HF aqueous is added slowly to the reactionsolution and the reaction stirred in the ice/water bath for 20 minutes.The reaction is monitored by TLC for disappearance of the startingmaterial. The reaction is worked up by diluting the reaction solution byadding 200 mL EtOAc and quenching the acid by adding 25 mL saturatedsodium bicarbonate solution to the bottle and stirring for 10 minutes.The solution is then transferred to a separatory funnel and the organicpartition washed with water until the pH of the water wash isapproximately 7, then washed with brine. The organic partition is driedover sodium sulfate and then evaporated to a solid of formula 21. The2′-O-protecting group may be removed from formula 21 to give formula 22as shown in Scheme 3. To a 50 mL Teflon bottle equipped with a magneticstir bar was charged, 500 mg of the compound of formula 21 and 5 mLanhydrous THF. Next, 1 mL HF-pyridine solution was slowly charged to thereaction solution. The reaction was stirred at room temperature for 1hour; reaction progress was monitored by TLC and/or HPLC fordisappearance of starting material. The reaction was worked up by adding10 mL EtOAc to the bottle to dilute the reaction solution and thensaturated sodium bicarbonate was slowly added to the bottle toneutralize the HF. The solution was transferred to a separatory funneland the organic partition was washed with 10 wt % sodium bicarbonatesolution then water until the pH of the water wash was approximately 7.Then the organic partition was washed with brine and then dried oversodium sulfate before evaporating to a solid of Formula (22). Further,as indicated above, the 2′- and 7-positions of the compound of formula20 may be deprotected in a one-step procedure usingtetrabutylammoniumfluoride (TBAF) to directly produce formula 22. A 1OmL RBF equipped with a magnetic stir bar was charged with 100 mg of thecompound of formula 20 and 5 mL EtOAc or THF to dissolve the taxane.Next, 100 μL of IM TBAF in THF was charged to the flask and the reactionwas stirred at room temperature for 1 hour; the reaction was monitoredby TLC and/or HPLC for disappearance of starting material. The reactionwas worked up by washing the reaction solution with water and thenbrine. The organic partition was dried over sodium sulfate andevaporated to a solid of formula 22. This method removes both the2′-0-TBDMS protecting group and the 7-O-TES protecting group. As shownfor example in Scheme 4, the compound of formula 22 may be protected asa 7,9-acetal, such as a cyclic acetal such as with anisaldehyde dimethylacetal to form a compound of formula 23.

To a 50 mL RBF was charged 1.15 g (1.35 mmol) of the compound of formula22 and 25 mL anhydrous DCM, under nitrogen. 343 μL (2.02 mmol, 1.5 eq.)anisaldehyde dimethyl acetal was charged to the flask, followed by 51 mg(0.269 mmol, 0.2 eq.) p-toluenesulfonic acid (PTSA). The reaction wasstirred at room temperature for 45 minutes then was worked up byextracting the product with EtOAc and washing with saturated sodiumbicarbonate solution followed by water. The organic partition wasevaporated to yield approximately 1.5 g of crude product. The crudeproduct was purified by flash chromatography to yield 0.72 g of pureproduct of formula 23. Next, the side chain was cleaved to form thecompound of formula 24. To a 25 mL RBF was charged 720 mg (0.740 mmol)of the compound of formula 23 and 15 mL anhydrous THF, under nitrogen.The flask was placed in an ice/water/ammonium chloride, −13° C. bath.Solid lithium borohydride (29.0 mg, 1.33 mmol, 1.8 eq.) was charged tothe reaction flask and the reaction stirred at −13° C. for two hoursbefore raising the temperature to 0° C. The reaction was worked up afterfive hours fifteen minutes by diluting with EtOAc and washing with waterand ammonium chloride solution. The organic partition was evaporated toyield 650 mg of crude compound but HPLC indicated that there was onlyapproximately 20% product and mostly unreacted starting material;therefore, the reaction was restarted by repeating the above procedureand running the reaction for an additional six hours. The organicpartition was evaporated to yield approximately 660 mg of crude product.The compound was purified on a spherical silica column to yield thecompound of formula 24.

The compound of formula 24 was then coupled with formula 25 to providethe compound of formula 26. To a 5 mL RBF was charged 180 mg (0.255mmol) of the compound of formula 24 and 105 mg (0.510 mmol, 2.0 eq.)DCC. Toluene (2 mL) was then added to dissolve the solids. Next, formula28 (158 mg, 0.383 mmol, 1.5 eq.) was dissolved in 1.0 mL DCM and thesolution was charged to the reaction flask followed by 6 mg (0.038 mmol,0.15 eq.) 4-PP. The reaction was stirred at room temperature for 23hours and then was quenched by adding 11.5 μL acetic acid and 4 μL waterand stirring for one hour. MTBE was added to the reaction flask toprecipitate DCU and the reaction solution was filtered to remove theprecipitate. The filtrate was slurried with activated carbon then passedacross a silica plug to remove the 4-PP salts. The eluent was evaporatedto a solid to yield 271 mg of crude coupled product of formula 26.

The 7,9-acetal and N,O-acetal protecting groups may then be removed andan N-acyl group added to form the compounds of formula 27 and 28, whichmay be separated from each other by liquid chromatography or kepttogether for the next step. While the same anisaldehyde group is used atboth the 7,9-acetal and N,O-acetal in the exemplary compound of formula26, such that both groups may be removed in a single step, it should beappreciated that other acetal protecting groups are contemplated suchthat multiple deprotection steps may be required. To a 10 mL RBF wascharged, 270 mg (0.245 mmol) of the compound of formula 26, 220 mg (0.8g/g coupled ester) Degussa type palladium on carbon, and 4.1 mL THF. Ina separate vial, 99 μL cone. HCl was diluted in 198 μL water and 1.0 mLTHF. This solution was added to the reaction flask and the flask wassealed and placed under hydrogen. The hydrogenation reaction was stirredfor 31 hours then was quenched by removing the hydrogen and filteringthe catalyst from the reaction solution then adding 84.5 μL (0.368 mmol,1.5 eq.) t-butoxy carbonyl (t-BOC) anhydride followed by 684 μL TEA. Thereaction stirred an additional 21 hours and then was worked up, dilutingthe filtrate with EtOAc and washing with water. The organic partitionwas evaporated to approximately 370 mg of oil. The oil was purifiedfirst by flash chromatography, then preparative TLC (PTLC) then by asemi-prep reverse phase column to yield 3.9 mg of pure product offormula 27 and 28.

A 7,9-acetal may then be formed to provide the compound of formula 3. Ina HPLC vial insert, 3.4 mg (4.13 μmol) of the compounds of formula 27and 28 was charged followed by 70 μL DCM. Next, 12.8 μL of a 1 to 20diluted acrolein dimethyl acetal in DCM (0.64 μL acetal, 5.37 μmol, 1.3eq.) was charged to the insert followed by 8.4 μL (0.413 μmol, 0.1 eq.)of a 0.05M PTSA solution in DCM. The reaction was lightly agitated thensat at room temperature. The reaction took more additions of the acetalsolution to drive it to completion then was worked up after a couple ofdays by filtering the solution through approximately 80 mg of basicactivated alumina. The alumina was washed with DCM then EtOAc and thefractions evaporated to dryness. The crude compound was purified on anormal phase analytical column to yield 605 μg of the compound offormula 3. In one example, the compound of formula 3 may then beseparated into its individual diastereoisomers to produce the compoundof formula S-(1) via chromatography using a solvent composition of 35%MTBE in heptane as described in the examples.

As generally described and specifically exemplified above, theseprocesses may be performed with the isolation of one or more of theintermediate compounds, or the process may be performed without theisolation and purification at each and every single processing steps.Standard procedures and chemical transformation and related methods arewell known to one skilled in the art, and such methods and procedureshave been described, for example, in standard references such asFiesers' Reagents for Organic Synthesis, John Wiley and Sons, New York,N.Y., 2002; Organic Reactions, vols. 1-83, John Wiley and Sons, NewYork, N.Y., 2006; March J. and Smith M.: Advanced Organic Chemistry,6^(th) ed., John Wiley and Sons, New York, N.Y.; and Larock R. C.:Comprehensive Organic Transformations, Wiley-VCH Publishers, New York,1999.

Accordingly, the invention additionally provides a process for thepreparation of the compound of formula S-(1), which comprises separationof the S-(1) isomer from a mixture with the R-(1) isomer bychromatography. The invention additionally provides a process for thepreparation of the compound of formula S-(1), which comprises separationof the S-(1) isomer from a mixture with the R-(1) isomer and thecompound of formula (2) by chromatography. Preferably, the compound offormula S-(1) is prepared by reaction of the compound of formula (13)with 3,3-dimethoxy-1-propene to give the acetal compound of formula (3)followed by isolation of the compound of formula S-(1) bychromatography. The chromatography is preferably conducted using silicagel as herein described. An alternative method for synthesizing thecompound of formula (1) is shown in Scheme 5.

A preferred method for synthesizing the compound of formula (1) is shownin Scheme 6.

Another preferred method for synthesizing the compound of formula (1) isdetailed below with reference to Scheme 7.

I. Oxidation of 10 DAB III, Formula (4):

A 4 L reaction flask, rinsed with dried EtOAc (300 niL) and held underN₂, was charged with dried EtOAc (1250 mL). Agitation was begun anddried (4) (100 g, 0.184 mol) was added. The addition of USP EtOH (800mL) followed and the reaction mixture was cooled to −1.3° C. (internaltemperature). Anhydrous CuCl₂ (86.4 g, 3.5 eq) was added and solids fromthe sides of the flask were washed into the mixture with anhydrous EtOH(450 mL). The reaction mixture was cooled to <−13° C. and anhydrous TEA(90 mL, 3.5 eq) was added slowly. The reaction was monitored byHPLC/TLC. At 1 h the reaction was judged complete (<5% (4)). TFA (36 mL)was added to quench the reaction and stirring continued for 15 min. Thereaction mixture was transferred to a 10 L rotovap flask.

EtOAc (500 mL) and EtOH (300 mL) were added to the reaction flask,stirred for 2 min and the rinse added to the contents of the rotovapflask, which was evaporated on the rotovap at 40° C. until no furtherdistillation occurred (80 min). Acidified ethanol (300 mL) was added tothe residue and the resulting slurry was transferred to a 2 L rotovapflask. The first rotovap flask was rinsed into the second with acidifiedEtOH (400 mL).

Again, the mixture was evaporated on the rotovap at 40° C. until nofurther distillation occurred (1 h). Acidified ethanol (305 niL) wasadded to the rotovap flask and the mixture was stirred on the rotovap at40° C. for 10 min. The contents of the flask were then cooled to 5° C.and filtered. The rotovap flask was rinsed (2×) with cold (2° C.)acidified ethanol (300 mL) and the rinse was transferred completely tothe filter to wash the solids. The solids were dried in the vacuum ovenovernight at 45° C. to give (29a). HPLC Area %=91.3%. Yield=96.72 g.

II. Tesylation of (29a) to Form (30):

To (29a) (96.72 g, 0.1783 mmol) in a 10 L rotovap flask was added ethylacetate (3000 mL, 30 mL/g). The solution was evaporated on the rotovapat 40° C. to approximately half the original volume (distilledvolume=1680 mL). Toluene (1000 mL, 10 mL/g) was added to the remainingsolution and it was evaporated on the rotovap at 40° C. until solidswere obtained (45 min). The solids were suspended in toluene (1000 mL,10 mL/g) and the suspension was evaporated on the rotovap at 40° C. (˜1h) to dry solids. The solids were transferred to a 2 L flask equippedwith a mechanical stirrer, thermocouple, addition funnel and N₂ stream(previously purged for 5 min). The solids in the rotovap flask wererinsed into the reaction flask with anhydrous pyridine (292 mL, 3 mL/g)and agitation was begun. Upon dissolution, agitation was continued andthe contents of the flask were cooled to −20° C. Triethylsilyltrifluoromethanesulfonate (120.9 mL, 3.0 eq) was slowly added to thereaction mixture to maintain the internal temperature of the reaction at<−10° C. After the addition of TES-OTf was complete, the reactionmixture was allowed to warm to −5.8° C. and agitation continued. Thirtyminutes after the addition of TES-OTf, sampling was begun and continuedat thirty-minute intervals for HPLC/TLC. The reaction was judgedcomplete at 2 h when HPLC/TLC indicated <2% mono-TES derivativeremaining. The reaction mixture was cooled to −17.5° C. Methanol (19.3mL, 0.2 mL/g) was added to quench the reaction and the reaction mixturewas stirred for 5 min. While allowing the mixture to warm to ambienttemperature, MTBE (500 mL) was slowly added with stirring and themixture was transferred to a separatory funnel.

Residues remaining in the reaction flask were washed into the separatoryfunnel with additional MTBE (200 mL, 2 mL/g), then water (250 mL, 2.5mL/g) and saturated NH₄Cl solution (250 mL, 2.5 mL/g) were added. Themixture was agitated and the layers were separated. The organic layerwas transferred to a clean container. MTBE (250 mL, 2 mL/g) was added tothe aqueous layer. It was agitated and the layers were separated. Thesecond organic layer was washed into the first organic layer with MTBE(100 mL) and water (200 mL, 2 mL/g) was added to the combined layers.This mixture was agitated and the layers were separated. The organiclayer was transferred to a 2 L rotovap flask and evaporated to a residueat 40° C. n-Heptane (500 mL, 5 mL/g) was added to this residue and thesolution was again evaporated to a residue at 40° C. n-Heptane (1000 mL,˜10 mL/g) was added again and the solution was evaporated to one-half ofits volume (distilled volume=375 mL). n-Heptane (300 mL, ˜2.5 mL/g) wasadded and the solution was stirred for 35 min on the rotovap at 40° C.The solution was then cooled to −15.7° C. while stirring was continuedfor ˜2.5 h. The solution was filtered. The solids remaining in the flaskwere rinsed into the filtration funnel with cold (<5° C.) n-heptane (100mL) and all the solids were collected and dried overnight in the vacuumoven to give 111.2 g (30). HPLC Area % purity=93.4%.

III. Reduction of (30) to Prepare (31):

To a stirred solution of THF (560 mL, 5 mL/g) under N₂ in a 4 L reactionflask, was added (30) (111 g, 0.144 mol,) followed by anhydrous ethanol(560 mL, 5 mL/g). The mixture was stirred to dissolve the solids andthen cooled to −12° C. 2 M LiBH₄ in THF (72 mL) was added slowly tocontrol the reaction temperature (temp=−11.9 to −9.7° C.). The reactionmixture was stirred and sampled for HPLC/TLC at 30 min intervals.Additional 2 M LiBH₄ in THF was introduced slowly (72 mL, 1.0 eq) to thereaction flask (temp=−9.6° C. to −7.1° C.) and agitation continued for30 min. A third addition of 2 M LiBH₄ in THF (36 mL, 0.5 eq) was made inthe same manner as the previous additions (temp=−7.6° C. to −6.7° C.),but with the bath temperature adjusted to 15° C. following the additionof the LiBH₄ solution and to 12.5° C. ten minutes later. At 1 hfollowing the final LiBH₄ addition, the reaction was judged complete(mono reduced product <3% relative to (31)). The reaction mixture wascooled to −10.8° C. and 10% ammonium acetate in EtOH (560 mL) was addedslowly and cautiously to allow the foam to settle and to control thetemperature of the solution <−3° C. The reaction mixture was transferredto a 2 L rotovap flask and any residues in the reaction flask wererinsed into the rotovap flask with EtOH (250 mL) and the contents of therotovap flask were evaporated on the rotovap at 40° C. to an oil.Methanol (560 mL) was added to the residue. Water (170O mL) was added toa 5 L flask equipped with an addition funnel and mechanical stirrer andwas vigorously agitated. To precipitate the product, the methanolsolution of the reaction mixture (748 mL) was slowly added to the flaskcontaining water. The resulting mixture was filtered and the solids werewashed with water (650 mL). A portion of the water was used to washsolids remaining in the precipitation flask into the filtration funnel.The solids were placed in the vacuum oven overnight at 45° C. to give139.5 g of slightly wet non-homogeneous product, (31). HPLC area %purity=92.8%.

IV. Acetylation/Deprotection of (31) to Prepare (33):

Acetylation: To (31) (138 g, 0.178 mol) in a 2 L rotovap flask was addedIPAc (1400 mL, 10 mL/g). The solution was evaporated on the rotovap at40° C. to an oil. The procedure was repeated. Dried IPAc (550 mL) wasthen added to the residual oil and the contents of the rotovap flaskwere transferred to a 1 L reaction flask, equipped with a mechanicalstirrer, addition funnel, thermocouple and a N₂ stream. The rotovapflask was washed into the reaction flask with IPAc (140 mL). DMAP (8.72g, 0.4 eq), anhydrous TEA (170 mL, 7 eq) and acetic anhydride (100.6 mL,6 eq) were added to the contents of the reaction flask and the mixturewas stirred and heated to 35° C. While continuing agitation and heatingto 35° C., the reaction was monitored by HPLC/TLC at 1-hour intervals.Upon completion of the reaction, as indicated by the absence of (31) (3h total time), the reaction mixture was cooled to 19.7° C. and saturatedammonium chloride solution (552 mL) was added. After stirring for 15min, the mixture was transferred to a separatory funnel, the layers wereseparated and the aqueous layer was removed. Water (280 mL) was added tothe organic layer and the mixture was stirred for 4 min. The layers wereagain separated and the aqueous layer was removed. The organic layer wastransferred to a 2 L rotovap flask and the remaining content of theseparatory funnel was washed into the rotovap flask with IPAc (200 mL).The mixture was evaporated to dryness on the rotovap at 40° C. to give−124 g (32) as pale yellow oily foam.

Deprotection: To the rotovap flask containing (32) (124 g) was addedmethanol (970 mL, 7 mL/g). Sampling for HPLC/TLC was begun and continuedat 1-hour intervals. The (32)/methanol solution was transferred to a 3 Lreaction flask and agitation was begun. The remaining content of therotovap flask was washed into the reaction flask with methanol (400 mL).Acetic acid (410 mL, 3 mL/g) and water (275 mL, 2 mL/g) were added andthe reaction mixture was heated to 50° C. and stirred. With thetemperature maintained between 50° C. and 55° C., the reaction wasmonitored by HPLC/TLC at 1-hour intervals for the disappearance of thestarting material, formation and disappearance of the mono-TESintermediate and formation of the product, (33). Upon completion (˜9 h),the reaction mixture was cooled to rt and transferred to a 10 L rotovapflask. Solvent exchanges to n-heptane (2×1370 niL, 1×1000 mL) and IPAc(2×1370 mL, 1×1500 mL) were performed. IPAc (280 mL, 2 mL/g) and silica(14O g, 1 g/g) were added to the rotovap flask and the contents wereevaporated on the rotovap at 40° C. until no further distillationoccurred and free flowing solids were obtained. The dry silica mixturewas loaded onto a silica pad (7 cm column, 280 g silica), conditionedwith 2:1 n-heptane/IPAc (500 mL, 2 mL/g silica) and washed (4×) with 2:1n-heptane/IPAc, 2 mL/g silica, 3400 mL total) and (4×) with 1:1n-heptane/IPAc (3020 mL total, 2 mL/g silica) until all impurities wereremoved as indicated by TLC. Each wash (−840 mL) was collected as aseparate fraction and analyzed by TLC. The silica pad was then washed(5×) with waEtOAc (1% water, 1% AcOH in EtOAc) (3950 mL total, 2 mL/gsilica) and with 1:1 MeOH/EtOAc and each wash (˜840 mL) was collected asa separate fraction. The product eluted with fractions 11-15. Thefractions containing (33) as indicated by HPLC/TLC were combined,transferred to a rotovap flask and evaporated to dryness on the rotovapat 40° C. The residue in the flask was dissolved and evaporated todryness: first with IPAc (1055 mL) and n-heptane (550 mL) and a secondtime with IPAc (830 mL) and n-heptane (410 mL). IPAc (500 mL) was thenadded to the residue, the solution was transferred to a 2 L round bottomflask and n-heptane (140 mL) was added. The resulting solution wasevaporated on the rotovap and dried in the vacuum oven at 40° C. to give(33) as foam. To dissolve the foam, IPAc (160 mL) was added to the flaskfollowed by toluene (800 mL). The solution was evaporated on the rotovapunder vacuum at 50° C. until half of the solvent was removed and solidswere forming. The contents of the flask were stirred and cooled to 21°C. for 1.5 h. The solids were filtered in a 90 cm filtration funnel on#54 Whatman filter paper and were washed with toluene (165 mL),transferred to the vacuum oven and dried at 40° C. to give 62.6 g of(33). HPLC area %=96.9%

VI. Acetal Formation: (33) to (34)

To a 3 L reaction flask containing (33) (25 g, 42.4 mmol) was addedtoluene (375 mL) and the reaction mixture was cooled to −15° C. TFA (9.8mL, 3.0 eq) was slowly added. This was followed by the addition ofacrolein diethyl acetal (8.7 g) and the reaction was monitored by HPLCuntil <3% of (33) remained. Hydrated silica was prepared by mixingsilica (25 g) and water (25%) and a “basified silica” mixture wasprepared by mixing a solution OfK₂CO₃ (17.6 g, 3.0 eq) in water (1 mL/g(33)) with 50 g silica. Upon reaction completion, the hydrated silicawas added to the reaction mixture and it was stirred for 30 to 45 minwhile maintaining the temperature <5° C. The basified silica was thenadded to the mixture while continuing to maintain the temperature <5° C.and the pH>5. After stirring for ˜15 min, the mixture was filtered. Thesilica was washed with −20 mL/g toluene and the filtrates were combinedand concentrated. The residue was digested with 1 mL/g toluene for ˜4 h.The resultant solids were filtered and washed with 80:20 toluene/heptaneto give 25 g of (34). HPLC area %=98%. Mass yield=66%.

VII. Preparation of Compound (1) from (34):

To THF (300 niL, 8 mL/g) stirring in a 1 L reaction flask (rinsed withTHF (500 mL)) was added (34) (35.7 g, 0.0570 mol). Purified (35a) (30.9g, 1.25 eq) was added to the reaction mixture followed by the additionof NMM (11.5 mL, 1.8 eq), DMAP (2.77 g, 0.4 eq) and THF (75 mL, 2 mL/g).The mixture was stirred while N₂ was bubbled from the bottom of theflask to mix and dissolve the solids. Pivaloyl chloride (11.5 mL, 1.6eq) was then added slowly to the reaction mixture. The reaction mixturewas warmed and the temperature maintained at 38° C.±4° C. while stirringcontinued and N₂ continued to be bubbled from the bottom of the flask.The reaction mixture was analyzed by HPLC/TLC for consumption ofstarting material and formation of the coupled ester, (36a), at 30 minintervals beginning 30 min after the addition of the pivaloyl chloride.After 1 h the reaction was judged complete and the reaction mixture wascooled to 2° C. 0.5 N HCl in MeOH (280 mL, −20 mL/mL NMM) was added tomaintain the pH of the reaction mixture=1.5-1.9. The reaction mixturewas stirred at 2° C.±2° C. and monitored by HPLC/TLC at 30 min intervalsfor consumption of (36a) and formation of (1) and the acrolein acetalhydrolyzed by-product. Upon completion at 2 h the reaction was quenchedwith 5% aqueous sodium bicarbonate (300 mL) and IPAc (185 mL, 5 mL/g)was added. The reaction mixture was transferred to a 2 L rotovap flaskand the reaction flask rinsed into the rotovap flask 2× with 60 mL IPAc.The mixture was evaporated under vacuum at 40° C. until a mixture of oiland water was obtained. EPAc (20O mL) was added to the oil and watermixture and the contents of the flask were transferred to a separatoryfunnel. The reaction flask was rinsed into the separatory funnel withIPAc (100 mL) and the contents of the separatory funnel were agitatedand the layers were separated. The aqueous layer was removed. Water (70mL) was added to the organic layer and, after agitation, the layers wereseparated and the aqueous layer was removed. The organic layer wastransferred to a rotovap flask and evaporated under vacuum at 40° C. toa foam, which was dried in the vacuum oven to give 64.8 g crude (1).HPLC area %=45.5%.

VIII. Purification Procedures:

Normal Phase Chromatography: The 6″ Varian DAC column was packed withKromasil (5 Kg, 1O μm, 100 A normal phase silica gel). The 50-cm bedlength provided a 9 L empty column volume (eCV). The column had beenregenerated (1 eCV 80:20 waMTBEMeOH) and re-equilibrated (IeCV waMTBE, 1eCV 65:35 n-heptane: waMTBE). The crude (1) (64.70 g), was dissolved inMTBE (180 mL) and heated to ˜40° C. n-Heptane (280 mL) was slowly addedto the solution. This load solution was pumped onto the column using aFMI “Q” pump. The column was then eluted with 65:35 n-heptane:waMTBE at800 mL/min. A 34 L forerun (˜3.8 eCV) was collected followed by 24fractions (500 mL each). Fractions 1 through 23 were combined andconcentrated to dryness on a rotovapor. The residue was dried in thevacuum oven overnight to provide 41.74 g (1). HPLC area %=99.4%.

Final Purification: The normal phase pool was dissolved in USP EtOH (6mL/g) and concentrated to dryness three times. The resultant residue wasdissolved in USP EtOH (2 mL/g). This ethanolic solution was slowly addeddrop-wise to water (deionized, 20 mL/g) with vigorous stirring. Theresultant solids were vacuum filtered and washed with cold DI water. Thesolids were dried in the vacuum oven at 40° C. overnight to give 38.85 g(1). HPLC area %=99.5%.

IX. Coupling of (35b) to (34) to Form (1):

Anhydride/Coupling (35b) with (34):

A 10 mL round bottom flask with two necks was heated to eliminate water,then allowed to cool under N₂ atmosphere. To the flask was added (34)(125 mg, 0.2 mmol), THF (1.25 mL), 4-methylmorpholine (40 μL, 0.36mmol), DMAP (10.9 mg, 0.009 mmol), (35b) sodium salt (110 mg, 0.254mmol) and finally trimethylacetyl chloride (40 μL, 0.319 mmol). Thereaction mixture was stirred at 40° C. under N₂. After about 2 hours,additional 4-methylmorpholine (11 μL, 0.01 mmol), (35b) sodium salt (41mg, 0.1 mmol) and trimethylacetyl chloride (13 μL, 0.1 mmol) were addedto assist formation of the anhydride intermediate which then coupled to(34).

After about 2 additional hours, 4-methylmorpholine (11 μL, 0.010 mmol),trimethylacetyl chloride (13 μL, 0.104 mmol) and (35b) sodium salt (42mg, 0.1 mmol) were added. After 1.5 hours more, the reaction was placedinto a freezer at −20° C. overnight. The following morning, stirring wasresumed and the reaction was heated to 45° C. for 2 hours. Additional4-methylmorpholine (22 μL, 0.02 mmol) and trimethylacetyl chloride (25μL, 0.201 mmol) were added. An additional 2 hours of stirring resultedin the reaction reaching −90% completion. To quench, the reactionmixture was removed from heat and allowed to cool to RT with stirring,and MTBE (2 mL) was added followed by water (1 mL). The mixture waspartitioned and the organic phase was washed with brine (40 μL). Theorganic phase was concentrated at 40° C. to obtain crude product as apink foam. The pink foam was dissolved into MTBE (500 μL) and addeddropwise to stirring n-heptane (5 mL) at −20° C. to give pinkprecipitate. The mixture was vacuum filtered and the solids were driedovernight in a vacuum oven at 40° C. to yield the desired coupled ester(82 mg), as indicated by LC/MS. The coupled ester (36b) was purified byflash chromatography on normal phase silica, eluting with anIPAc/n-heptane system of increasing polarity.

Approximately 26 mg of the purified coupled ester (36b) was recovered asconfirmed by LC/MS.

Deprotection of (36b) to form (1):

The coupled ester (36b) (15 mg, 0.001 mmol) was dissolved into THF (1mL). A 250 μL, aliquot of the solution was diluted 1:1 with THF. Thesolution was stirred on an ice bath at ˜0° C., after which HCl (0.5 N inMeOH, 25 μL) was added. The reaction was monitored by LC/MS, whichindicated the formation of (1).

Methods for the preparation of the compounds of formula 35a (the2,6-dimethoxy coupling agent) and 35b (the 2,4-dimethoxy coupling agent)and further suitable coupling conditions for converting the compound offormula (34) into the compound of formula (1) are described in WO2007/126893.

Chemical Example 1

Separation of diastereoisomers of formula (3) by Normal PhaseChromatography.

A solution of the compound of formula (3), which comprises a mixture ofdiasteroisomers of formula (1) and formula (2) (570 mg) was concentratedto light yellow oil, dried in the vacuum oven for 15 min andre-dissolved in 35:65 MTBE/n-heptane. The solution was loaded onto aflash chromatography column packed with spherical silica (YMC-1701, 56g), which had been conditioned with 35:65 MTBE/n-heptane. The solutionflask was rinsed (2×) with ˜2 mL of MTBE onto the column. The column waseluted with 35:65 MTBE/n-heptane and fractions (25 mL) were collected.Fractions containing the pure product (fractions 23-25) as indicated byvisual spotting (to identify the elution of UV active material) and byTLC analysis (50:50 MTBE/n-heptane) were collected, pooled andconcentrated to give 305 mg of the diastereoisomer of formula S-(1) as awhite solid.

The compound S-(1) was characterized by NMR, including ¹H, ¹³C, HMBC,HSQC, NOESY, COSY and gHSQMBC. The compound of formula S-(1) was alsoanalyzed by β-tubulin binding modeling studies. Similarly compound R-(1)was also characterized by NMR, including ¹H, ¹³C, HMBC, HSQC, NOESY,COSY and gHSQMBC. The compound of the formula (1) may be used to providesingle isomers by chromatography over spherical silica.

Properties and Uses of Compounds

The compound of the formula (1) also has the extremely surprisingproperty of being effective after oral administration. The brain cancerto be treated may be a neuroblastoma. The brain cancer to be treated maybe a glioblastoma. In another aspect of the above embodiment, thetherapeutic further comprises one or more chemotherapeutic agentsselected from the group consisting of aromatase inhibitors,antiestrogen, anti-androgen, a gonadorelin agonists, topoisomerase 1inhibitors, topoisomerase 2 inhibitors, microtubule active agents,alkylating agents, anthracyclines, corticosteroids, IMiDs, proteaseinhibitors, IGF-I inhibitors, CD40 antibodies, Smac mimetics, FGF3modulators, mTOR inhibitors, HDAC inhibitors, IKK inhibitors, P38MAPKinhibitors, HSP90 inhibitors, akt inhibitors, antineoplastic agents,antimetabolites, platin containing compounds, lipid- or proteinkinase-targeting agents, protein- or lipid phosphatase-targeting agents,anti-angiogentic agents, agents that induce cell differentiation,bradykinin 1 receptor antagonists, angiotensin II antagonists,cyclooxygenase inhibitors, heparanase inhibitors, lymphokine inhibitors,cytokine inhibitors, bisphosphanates, rapamycin derivatives,anti-apoptotic pathway inhibitors, apoptotic pathway agonists, PPARagonists, inhibitors of Ras isoforms, telomerase inhibitors, proteaseinhibitors, metalloproteinase inhibitors, and aminopeptidase inhibitors.

In another aspect of the above embodiment, the therapeutic furthercomprises one or more pharmaceutically acceptable, inert orphysiologically active diluents or adjuvants selected from the groupconsisting of cytostatic agent, cytotoxic agent, taxane, topoisomeraseII inhibitor, topoisomerase I inhibitor, tubulin interacting agent,antibodies, antiangiogenics, COX-2 inhibitors, hormonal agent,thymidilate synthase inhibitor, anti-metabolite, alkylating agent,farnesyl protein transferase inhibitor, signal transduction inhibitor,EGFR kinase inhibitor, antibody to EGFR, C-abl kinase inhibitor,hormonal therapy combination and aromatase combination.

In another aspect of the above embodiment, the one or morepharmaceutically acceptable, inert or physiologically active diluents oradjuvants is selected from the group consisting of temozolomide, uracilmustard, chiormethine, ifosfamide, melphalan, chlorambucil, pipobroman,triethylenemelaniine, triethylenethiophosphoramine, busulfan,carmustine, lomustine, streptozocin, dacarbazine, floxuridine,cytarabine, 6-mercaptopurine, 6-thioguanine, fludarabine phosphate,oxaliplatin, leucovirin, oxaliplatin, pentostatine, vinblastine,vincristine, vindesine, bleomycin, dactinomycin, daunorubicin,doxorubicin, epirubicin, idarubicin, mithramycin, deoxycoformycin,mitomycin-c, 1-asparaginase, teniposide i 7a-ethinylestradiol,diethylstilbestrol, testosterone, prednisone, fluoxymesterone,dromostanolone propionate, testolactone, megestrolacetate,methylprednisolone, methyltestosterone, prednisolone, triamcinolone,chlorotrianisene, hydroxyprogesterone, aminoglutethimide, estramustine,medroxyprogesteroneacetate, leuprolide, flutamide, toremifene,goserelin, cisplatin, carboplatin, hydroxyurea, amsacrine, procarbazine,mitotane, mitoxantrone, levamisole, navelbene, anastrazole, letrazole,capecitabine, reloxafine, droloxafine, hexamethylmelamine, doxorubicin,cyclophosphamide, gemcitabine, interferons, pegylated interferons,erbitux and mixtures thereof. In another aspect of the above embodiment,the therapeutic is administered alone or in combination withradiotherapy. Similarly it may be employed in conjunction with surgery.

In another aspect of the above embodiment, the other chemotherapeuticagent is temozolomide, cisplatin, 5-fluorouracil, taxotere orgemcitabine. Most aptly, the other chemotherapeutic agent is activeagainst brain cancer. In a favored aspect of the above embodiment, theother chemotherapeutic agent is temozolomide. In a further favoredaspect of the above embodiment the other chemotherapeutic agent isbevacizumab (Avastin™). In one aspect, the cancer to be treated is oneresponsive to microtubule stabilization. In one embodiment, theapplication also provides any of the above embodiments, furthercomprising administering one or more additional anti-cancer agents. Ifthe brain cancer is a metastasis the primary tumor or metastasesexternal to the brain may be simultaneously treated. In one aspect, theapplication also provides the above embodiment wherein the one or moreadditional anti-cancer agents act in a phase of the cell cycle otherthan the G2-M phase. In one aspect, the application also provides theabove embodiment wherein the one or more additional anti-cancer agentsis a thymidilate synthase inhibitor, a DNA cross linking agent, atopoisomerase I or II inhibitor, a DNA alkylating agent, a ribonuclasereductase inhibitor, a cytotoxic factor, or a growth factor inhibitor.In one embodiment, the application also provides any of the aboveembodiments, further comprising administering radiation therapy. In oneaspect, the application also provides the above embodiment incombination with surgical removal of a cancer.

In one aspect, the application also provides the above embodiment incombination with surgical removal of a cancer. In one embodiment, theapplication also provides any of the above embodiments, furthercomprising administering radiation therapy. In one aspect, theapplication also provides the above embodiment in combination withsurgical removal of a cancer. In another aspect, the application alsoprovides the above embodiment in combination with surgical removal of acancer.

In one embodiment, the application also provides any of the aboveembodiments, further comprising administering radiation therapy. In oneaspect, the application also provides the above embodiment incombination with surgical removal of a cancer. In another aspect, theapplication also provides the above embodiment in combination withsurgical removal of a cancer. In one embodiment, the application alsoprovides any of the above embodiments, further comprising administeringradiation therapy. In one aspect, the application also provides theabove embodiment in combination with surgical removal of a cancer. Inone aspect, the application also provides the above embodiment incombination with surgical removal of a cancer.

In one embodiment, the application also provides any of the aboveembodiments, aspects and variations, wherein the composition isadministered as a single infusion once every 21 days in a 21 day cycle.In one embodiment, the application also provides any of the aboveembodiments, wherein the compound of formula S-(1) or its single isomeras described above is administered as a single infusion once every sevendays, followed by a rest week, in a 28 day cycle. In one embodiment, theapplication also provides any of the above embodiments, wherein thecompound of formula S-(1) or its single isomer as described above isadministered in intravenously combination with one or more anti-cancertherapies.

In one aspect, the application also provides the above embodimentwherein the one or more anti-cancer therapies is a chemotherapeuticagent. In another variation of the above embodiment, the one or moreanti-cancer therapies is a radiotherapeutic agent.

In another variation of the above embodiment, the one or moreanti-cancer therapies is surgical removal of a tumor. In anothervariation of the above embodiment, the chemotherapeutic agent istemozolomide.

In one embodiment, the application also provides any of the aboveembodiments, wherein the compound of formula S-(1) or its single isomeras described above is administered intravenously before the otherchemotherapeutic agents. In one embodiment, the application alsoprovides any of the above embodiments, wherein the compound of formulaS-(1) or its single isomer as described above is administeredintravenously after the other chemotherapeutic agents. In anotherembodiment, the application also provides any of the above embodiments,wherein the compound of formula S-(1) or its single isomer as describedabove is administered intravenously before a radiotherapeutic agent. Inyet another embodiment, the application also provides any of the aboveembodiments, wherein the compound of formula S-(1) or its single isomeras described above is administered intravenously after aradiotherapeutic agent. In one embodiment, the application also providesany of the above embodiments, wherein the compound of formula S-(1) orits single isomer as described above is administered intravenouslybefore surgical removal.

In yet another embodiment, the application also provides any of theabove embodiments, wherein the compound of formula S-(1) or its singleisomer as described above is administered intravenously after surgicalremoval. In one embodiment, the application also provides a method ofpotentiating the therapeutic benefit of a multidrug chemotherapeuticregimen, wherein one of the drugs in the regimen comprises the compoundof formula S-(1) or its single isomer as described above, byadministering the compound of formula S-(1) or its single isomer asdescribed above as an intravenous formulation. In one aspect of theabove embodiment, said intravenous formulation comprises the compound offormula S-(1) or its single isomer as described above given at highdose. In another aspect of the above embodiment, wherein another drug inthe regimen comprises an anti-mitotic agent or anti-microtubule agent.In another aspect of the above embodiment, the dosage of a singleinfusion of the compound of formula S-(1) or its single isomer asdescribed above exceeds 160 Mg/M². In another aspect of the aboveembodiment, the dosage of a single infusion of the compound of formulaS-(1) or its single isomer as described above exceeds 185 Mg/M².

In one embodiment, the application also provides a method to produceprolonged elevated plasma levels of the compound of formula S-(1) or itssingle isomer as described above to promote synergistic interactionbetween the compound of formula S-(1) or its single isomer as describedabove and a second chemotherapeutic agent, wherein: the compound offormula S-(1) or its single isomer as described above is administered asan intravenous formulation, and the compound of formula S-(1) or itssingle isomer as described above is administered on the day of, orwithin 3 days of administration of said second chemotherapeutic agent.In one aspect of the above embodiment, said second chemotherapeuticagent comprises an anti-mitotic agent or anti-microtubule agent. Inanother aspect of the above embodiment, the intravenous formulationcomprises the compound of formula S-(1) or its single isomer asdescribed above. In one embodiment, the application also provides amethod of binding microtubules in cancer cells using the compound offormula S-(1) or its single isomer as described above. In anotherembodiment, the application also provides a method of hindering mitosisin cancer cells using the compound of formula S-(1) or its single isomeras described above. In one aspect of the above embodiment, the cancercells are brain cancer cells. In one aspect of the above embodiment, thecompound of formula S-(1) or its single isomer as described above is nota substrate for MDR protein. In one embodiment, the application alsoprovides any of the above embodiments wherein the compound of formulaS-(1) or its single isomer as described above is a singlediastereoisomer. In one embodiment, the application also provides any ofthe above embodiments wherein the compound of formula S-(1) or itssingle isomer as described above is a mixture of more than onediastereoisomer.

In one embodiment, the application also provides a method of assayingfor cancer cell sensitivity to the compound of formula S-(1) or itssingle isomer as described above comprising: a) providing a cancer cell;b) contacting the cancer cell with the compound of formula S-(1) or itssingle isomer as described above; c) analyzing the cancer cell forinhibition of growth; and d) comparing the inhibition of growth in thecancer cell from step (c) with the inhibition of growth in the cancercell in the absence of the compound of formula S-(1) or its singleisomer as described above, wherein growth inhibition by the compound offormula S-(1) or its single isomer as described above indicates thatsaid cancer cell is susceptible to the compound of formula S-(1) or itssingle isomer as described above. In one embodiment, the applicationalso provides the above embodiment, further comprising assaying forinhibition of tubulin disassembly in a cancer cell.

The invention also provides the compound of formula S-(1) or its singleisomer as described above for use in the treatment of brain cancer. Suchuse may be by oral administration, injection (for example intravenousinjection) or by other modes of administration. The invention alsoprovides the use of the compound of the formula S-(1) or its singleisomer as described above in the manufacture of a medicament for thetreatment of brain cancer. Such a medicament may be adapted to beadministered by oral administration, injection (for example intravenousinjection) or by other modes of administration. The brain cancer that istreated may be any that grows in the brain, including but not limitedto, astrocytoma, cramiopharyugioma, glioma, ependynoma, neuroglioma,oligodendroglioma, glioblastoma multiforme, meningioma, medalloblastomaand other primitive neuroectoderma.

The compound of formula S-(1) or its single isomers as described abovemay be administered by any conventional route of administrationincluding, but not limited to, oral, pulmonary, intraperitoneal (ip),intravenous (iv), intramuscular (im), subcutaneous (sc), transdermal,buccal, nasal, sublingual, ocular, rectal and vaginal. It will bereadily apparent to those skilled in the art that any dosage orfrequency of administration that provides the desired therapeutic effectis suitable for use in the present application. The therapeuticallyeffective amount of the compound of formula S-(1) or its single isomersas described above may be administered by week or by 21 days at about7-500 mg/m², or 7-240 mg/m², or 7-185 mg/m². The dosages, however, maybe varied depending on the requirements of the subject to be treated,including sex, age, weight, diet, etc. The precise amount of thecompound of formula S-(1) or its single isomers as described aboverequired to be administered depends on the judgment of the practitionerand is peculiar to each individual. Such amounts can often be reflectedin unit doses of about 200 mg to 400 mg, for example about 250 mg, 300mg or 350 mg. Another embodiment of the present application is apharmaceutical composition for treating brain tumor, comprising atherapeutically effective amount of the compound of formula S-(1) or itssingle isomers as described above and a pharmaceutically acceptablecarrier. To prepare a pharmaceutical composition of the presentapplication, the compound of formula S-(1) or its single isomers asdescribed above is admixed with a pharmaceutically acceptable carrieraccording to conventional pharmaceutical compounding techniques, whereinthe carrier may take a wide variety of forms depending on the form ofpreparation desired for administration. Suitable pharmaceuticallyacceptable carriers are well known in the art. Descriptions of somepharmaceutically acceptable carriers may be found in The Handbook ofPharmaceutical Excipients, Eds. Rowe et al., American PharmaceuticalAssociation and the Pharmaceutical Society of Great Britain.

The pharmaceutical composition of the present application may be in theform of a tablet, pill, capsule, granule, powder, ointment, gel, sterileparenteral solution or suspension, metered aerosol or liquid spray, orsuppository, depending on the administration route. As a solid dosageform, the pharmaceutical composition of the present application maycomprise, in addition to the compound of formula S-(1) or its singleisomers as described above, at least one diluent, binder, adhesive,disintegrant, lubricant, antiadherent, and/or glidant. Additionally,sweeteners, flavorants, colorants and/or coatings may be added forspecific purposes. As a liquid dosage form, the pharmaceuticalcomposition of the present application may comprise, in addition to thecompound of formula S-(1) or its single isomers as described above and aliquid vehicle, at least one wetting agent, dispersant, flocculationagent, thickener, buffer, osmotic agent, coloring agent, flavor,fragrance, and/or preservative.

The composition may contain the above taxane compound in a compositionalso comprising a polyoxyethylated castor oil. Many compositions willalso comprise ethanol.

Preferably, the polyethoxylated castor oil formulation is about 50%ethanol and about 50% polyethoxylated castor oil or about 85% ethanoland about 15% polyethoxylated castor oil. Such polyethoxylated casteroils include those available as Cremophor. Other suitable agents forinclusion in such formulations are as described in WO 99/45918. Suchadditional carriers include vitamin E TPGS, oleic acid, Tweens such asTween 80, butrol, solutrol and the like.

Such a possible liquid formulation includes a sterile solutioncontaining 10 mg/mL of the compound of formula S-(1) or its singleisomers as described above in a 15:85 or 50:50 (w/v) polyoxyl 35 castoroil/dehydrated alcohol solution. An appropriate pharmaceutical gradepolyoxyl 35 castor oil is Cremophor EL-P, which is a non-ionicsolubilizer made by reacting castor oil with ethylene oxide in a molarratio of 1:35, followed by a purification process (BASF Pharma). Fororal use such compositions need not be sterile.

It is believed that the compounds and hence compositions of thisinvention possess an enhanced safety profile (for example, on the immunesystem or the blood) in comparison to marketed taxanes which offers thepotential for enhanced or longer dosing schedules under the direction ofthe skilled physician than marketed taxanes. The compositions may fororal administration contain at least 30 mg/m2 of the compound of theinvention per dose, or at least 50, 80, 100, 150 mg/m2, or less than 250mg/ni2 per does (the average area for a patient being assumed to be 2mfor conversion to absolute weight). However, the dosage may be varied asdirected by the physician in view of the individual patient's response.

A liquid composition will normally contain about 0.1 mg/ml to about 15mg/ml for example about 0.5, 1, 2, 3, 5 or 10 mg/ml of the compound ofthe invention. A non-liquid composition may contain a higher proportionof the compound of the invention, for example 5% to 50%, such as 10, 20,25 or 30% by weight. WO 1999/45918 and the international patentapplications and US patent applications referred to above disclosescompositions that may be considered for use with compounds of theinvention.

The compound of the invention may be useful in the treatment of diseaseswhen used alone or in combination with other therapies. For example,when used for the treatment of cancer, the compounds of the inventionmay be administered alone or in combination with radiotherapy, surgicalremoval, hormonal agents, antibodies, antiangiogenics, COX-2 inhibitors,and/or other chemotherapeutic agents such as taxanes, temozolomide,cisplatin, 5-fluorouracil, taxotere, gemcitabine, topoisomerase IIinhibitor, topoisomerase I inhibitor, tubulin interacting agent,antibodies, antiangiogenics, COX-2 inhibitors, hormonal agent,thymidilate synthase inhibitor, anti-metabolite, alkylating agent,farnesyl protein transferase inhibitor, signal transduction inhibitor,EGFR kinase inhibitor, antibody to EGFR, C-abl kinase inhibitor,hormonal therapy combination, and aromatase combination.

The compound of the invention may be useful in the treatment of diseaseswhen used alone or in combination with other chemotherapeutics. Forexample, when used for the treatment of cancer, the compounds of theinvention may be administered alone or in combination with aromataseinhibitors, antiestrogen, anti-androgen, a gonadorelin agonists,topoisomerase 1 inhibitors, topoisomerase 2 inhibitors, microtubuleactive agents, alkylating agents, anthracyclines, corticosteroids,IMiDs, protease inhibitors, IGF-1 inhibitors, CD40 antibodies, Smacmimetics, FGF3 modulators, mTOR inhibitors, HDAC inhibitors, IKKinhibitors, P38MAPK inhibitors, HSP90 inhibitors, akt inhibitors,antineoplastic agents, antimetabolites, platin containing compounds,lipid- or protein kinase-targeting agents, protein- or lipidphosphatase-targeting agents, anti-angiogentic agents, agents thatinduce cell differentiation, bradykinin 1 receptor antagonists,angiotensin II antagonists, cyclooxygenase inhibitors, heparanaseinhibitors, lymphokine inhibitors, cytokine inhibitors, bisphosphanates,rapamycin derivatives, anti-apoptotic pathway inhibitors, apoptoticpathway agonists, PPAR agonists, inhibitors of Ras isoforms, telomeraseinhibitors, protease inhibitors, metalloproteinase inhibitors,aminopeptidase inhibitors, thymidilate synthase inhibitors, a DNA crosslinking agents, topoisomerase I or II inhibitors, DNA alkylating agents,ribonuclase reductase inhibitors, cytotoxic factors, and growth factorinhibitors.

The compound of the invention may be useful in the treatment of diseaseswhen used alone or in combination with other chemotherapeutics. Forexample, when used for the treatment of cancer, the compounds of theinvention may be administered alone or in combination withpharmaceutically acceptable, inert or physiologically active diluents oradjuvants is selected from the group consisting of temozolomide, uracilmustard, chiormethine, ifosfamide, melphalan, chlorambucil, pipobroman,triethylenemelaniine, triethylenethiophosphoramine, busulfan,carmustine, lomustine, streptozocin, dacarbazine, floxuridine,cytarabine, 6-mercaptopurine, 6-thioguanine, fludarabine phosphate,oxaliplatin, leucovirin, oxaliplatin, pentostatine, vinblastine,vincristine, vindesine, bleomycin, dactinomycin, daunorubicin,doxorubicin, epirubicin, idarubicin, mithramycin, deoxycoformycin,mitomycin-c, 1-asparaginase, teniposide i 7a-ethinylestradiol,diethyistilbestrol, testosterone, prednisone, fluoxymesterone,dromostanolone propionate, testolactone, megestrolacetate,methylprednisolone, methyltestosterone, prednisolone, triamcinolone,chlorotrianisene, hydroxyprogesterone, aminoglutethimide, estramustine,medroxyprogesteroneacetate, leuprolide, flutamide, toremifene,goserelin, cisplatin, carboplatin, hydroxyurea, amsacrine, procarbazine,mitotane, mitoxantrone, levamisole, navelbene, anastrazole, letrazole,capecitabine, reloxafine, droloxafme, hexamethylmelamine, doxorubicin,cyclophosphamide, gemcitabine, interferons, pegylated interferons,erbitux and mixtures thereof.

The compound of the invention may be useful in the treatment of diseaseswhen used alone or in combination with other chemotherapeutics. Forexample, when used for the treatment of cancer, the compounds of theinvention may be administered alone or in combination withpharmaceutically acceptable, inert or physiologically active diluents oradjuvants is selected from the group consisting of aromatase inhibitors,antiestrogen, anti-androgen, a gonadorelin agonists, topoisomerase 1inhibitors, topoisomerase 2 inhibitors, microtubule active agents,alkylating agents, anthracyclines, corticosteroids, IMiDs, proteaseinhibitors, IGF-I inhibitors, CD40 antibodies, Smac mimetics, FGF3modulators, mTOR inhibitors, HDAC inhibitors, IKK inhibitors, P38MAPKinhibitors, HSP90 inhibitors, akt inhibitors, antineoplastic agents,antimetabolites, platin containing compounds, lipid- or proteinkinase-targeting agents, protein- or lipid phosphatase-targeting agents,anti-angiogentic agents, agents that induce cell differentiation,bradykinin 1 receptor antagonists, angiotensin II antagonists,cyclooxygenase inhibitors, heparanase inhibitors, lymphokine inhibitors,cytokine inhibitors, bisphosphanates, rapamycin derivatives,anti-apoptotic pathway inhibitors, apoptotic pathway agonists, PPARagonists, inhibitors of Ras isoforms, telomerase inhibitors, proteaseinhibitors, metalloproteinase inhibitors, and aminopeptidase inhibitors.

FIGURES

FIG. 1. The compound of formula S-(1) crosses rat blood-brain barrier.

FIG. 2. Mouse Plasma and Brain Levels of the compound of formula S-(1)after single IV dose.

FIG. 3. Summary of U251 Orthotopic Intracranial Xenograft Study Data

FIG. 4. The compound of formula S-(1) Oral efficacy in Mice

FIG. 5. Oral Efficacy of the compound of formula S-(1) in NeuroblastomaXenograft FIG. 6. The compound of formula S-(1) Oral Efficacy in OvarianTumor Xenograft

FIG. 7. The compound of formula S-(1) Oral efficacy in GlioblastomaXenograft

FIG. 8. Oral efficacy of the compound of formula S-(1) in GlioblastomaXenograft Model

FIG. 9. IV efficacy of the compound of formula S-(1) in GlioblastomaXenograft Model

EXAMPLES In Vitro ED₅₀ MT Polymerization Study

In this tubulin binding assay, microtubule protein (MTP) is used as asubstrate. The assay contains bovine tubulin plus microtubule associatedproteins (MAP). MTP is polymerized into microtubules in the presence ofDAPI (4′,6′-diamidino-2-phenylindole), a fluorescent compound. DAPIbinds to tubulin; when microtubules are formed and there is anenhancement of fluorescence. The microtubule formation is measured as afunction of time, using a fluorescence plate reader. The ED50 valuesobtained with this method are in good agreement with older sedimentationtechniques. The more current assay, using DAPI, is faster and uses lessprotein. The method used is based on the procedure published by Donna M.Barron, et al, “Fluorescence-based high-throughput assay forantimicrotuble drugs” Analytical Biochemistry, 315: 49-56, 2003, whichis incorporated by reference in its entirety. The excitation wavelength,in that assay, was set at 370 nm and the emission wavelength was set at450 nm for the DAPI experiments.

A Bio-Tek FL 600 microplate Fluorescence Reader was used to measure therelative level of fluorescence in the DAPI assay.

Assays were conducted in 96-well plates. Each well contained a totalvolume of 0.1 niL consisting of PEM buffer (0.1 M Pipes, 1 mM EGTA, 1 mMMgCl₂, pH 6.9), 0.2 mg bovine microtubule protein, and 10 μg of DAPI.Compounds having paclitaxel-like activity of varying concentrationsdissolved in DMSO were added last. The final DMSO concentration was 4%.The plates were incubated at 37° C. for 30 minutes and read in afluorescence plate reader using an excitation wavelength of 360 nm andan emission wavelength of 460 nm. Fluorescence values were corrected forthe sample without compound. Results were expressed as a percent ofmaximum assembly, with maximum assembly taken to be that obtained at 25μM paclitaxel. Experiments were done twice in triplicate. Results weresubsequently combined and fit to a non-linear regression program. Theresults from these studies summarized in Table 2 indicate that the S-(1)diastereoisomer has an ED₅₀ potency that is equal to or greater thanthat determined for other tubulin binding agents such as paclitaxel,docetaxel and Epothilone B.

TABLE 2 Summary of Tubulin Polymerization Assays, Comparison of S-(1) topaclitaxel, docetaxel, and epothilone B. Compound ED50, μM ED50Compound/ED50 Paclitaxel S-(1) 1.58 ± 0.46 0.53 Paclitaxel 2.97 ± 0.501.00 Docetaxel 3.18 ± 0.45 1.07 Epothilone B 3.31 ± 0.51 1.11

MTS Proliferation Assay (Promega)

Day 1: Cells were plated in appropriate growth medium at 5×³ per well in100 ul in 96 well tissue culture plates, Falcon, one for each drug to betested. Col 1 was blank; it contained no cells, just medium. The plateswere incubated overnight at 37° C., 5% CO₂ to allow attachment.

Day 2: Added 120 ul growth medium in wells of 96-well “dilution plates”(one for each drug) and let sit in 37° C. incubator for about 1 hr.

Thawed DMSO drug stocks (usually at 10 mM). Each drug was diluted 6 ulinto a tube with 3 ml growth medium, to 20 uM.

Aspirated medium from col 12 of a dilution plate; added 200-300 ul of 20uM drug to wells of col 12. Made serial dilution down this 96-wellplate: for a 1:5 dilution pattern, moved 60 ul from col 12 to col 11,mixed 4-5 times (using 8 place multi-pipettor), moved 60 ul to col 10,etc. stopping at col 3.

Moved 100 ul of medium+drug from dilution plate to a cell plate, i.e.col 1 from drug plate (blank=no cells) to col 1 of cell plate, etc. upto col 12. Col 2 contained cells with no drug. Col 3 had the lowestconcentration of drug (0.005 nM) and col 12 had the highest drugconcentration (10 uM).

Day 4 or 5: Terminated the assay 48 to 72 hrs after drug addition.Thawed MTS reagent; made up enough medium+MTS to cover all plates at 115ul per well (100 ul medium+15 ul MTS). Aspirated medium+drugs from cellplate; replaced with medium+MTS mix and incubated 1-6 hrs (37° C., 5%CO₂), depending on cell type.

When the color turned dark in control wells (col 2), and was still lightin col 12, the absorbance at 490 nm was read on a plate reader; theresults were used to calculate IC₅₀.

The effects of the compound of formula S-(1) measured in in vitro andxenograft animal models of various brain cancers were evaluated in thefollowing experimental examples, which are intended to be a way ofillustrating but not limiting the present application.

S-(I) Pharmacokinetic Data in Mouse Model:

S-(I) was formulated in 7% Ethanol: 3% Cremophor EL: 90% D5W (5%Dextrose in water). The formulated drug was administered as a single IVbolus via tail vein injection. The details are set out below:

Animal Information:

Spe- Wt. Range Total No. Fast- Food cies Strain Sex (g) Required Sourceed Returned Mice CD-1 Male 20-30 36 CRL No NA

Group No. of Test Dose Volume Conc. Dose No. Animals Article VehicleRoute (mL/kg) (mg/mL) (mg/kg) 1 36 S-(1) 7% Ethanol: IV 10 2 20 3%Cremophor EL: (Tail Vein) 90% D5W

Sample Collection timing: Terminal blood (plasma) and brain specimenswere collected at 9 times post-dose, with 4 mice per sample time. Samplecollection times:

5, 15 min., 2, 8, 24, 32, 48, 72 and 96 hr post-dose (4 mice per sampletime).

Blood collection: A terminal blood sample was collected from each mousevia cardiac puncture. The whole blood was collected on wet ice, spundown immediately (at 4° C.), and plasma stored frozen at −20° C. untilanalysis. The anticoagulant used was K₂EDTA. Brain Sample Collection:Whole brains were removed by dissection. Brains were collected on wetice, weighed, and stored at −20° C.

TABLE 3 Mouse Plasma and Brain Levels of S-(1) after Single iv DoseBrain Plasma Cmax ng/ml Cmax ng/ml  3726.6  1550.2 AUC (0-t) ng-hr/mlAUC (0-t) ng-hr/ml 64984.9 16870.2 AUC (0-∞) ng-hr/ml AUC (0-∞) ng-hr/ml88742.9 16951.2 MRT (expo) hr MRT (expo) hr   42.5   17.6 CL ml/hr CLml/hr    0.006    0.024

The results indicate that S-(1) is not impeded by the blood-brainbarrier in the mouse model. See FIG. 2.

Antitumor Efficacy of S-(1) against Human U251 CNS Tumor Cells Implantedin Mouse Brain:

Additional studies were conducted in animal models to determine theefficacy of S-(1) against brain tumors. In one study, the anti-tumoractivity of S-(1) was evaluated both when administered alone and incombination with temozolomide, against intracerebrally (ic) implantedhuman U251 (glioblastoma) CNS tumor cells in male athymic nude mice.

Tumor Model: Each animal was implanted with one million U251 human CNStumor cells from an in vitro cell line by ic injection with a 25 gaugeneedle. The day of tumor implantation (May 24, 2006) was designated asday 0. A sufficient number of mice were implanted so that animals withbody weights in a range as narrow as possible were selected for thetrial on the day of treatment initiation (day 1 after tumorimplantation). Animals were randomly assigned to the treatment groupsand individually identified by earmark codes.

Drug Formulation: On each day of treatment, the appropriate amount ofS-(1) was formulated in 3% cremophor EL/7% ethanol/90% D5W at aconcentration of 2 mg/mL. A portion of this solution was then dilutedwith the complete vehicle to achieve the lower dosing concentration of1.2 mg/mL. Both concentrations of S-(1) were then kept at 37° C. andinjected within 30 minutes of formulation on the basis of exact bodyweight using a volume of 0.1 mL/10 g of body weight. Temozolomide(Temodar, Schering Corporation) was prepared on each day of injection inKlucel+tween 80 at a concentration of 4 mg/mL. Temozolomide wasadministered within 5 minutes of formulation on the basis of exact bodyweight using a volume of 0.2 mL/10 g of body weight.

Data Collection: Animal health surveillance was conducted and mortalitydata were collected daily. The animals were weighed twice weeklystarting with the first day of treatment.

Study Duration: The study was terminated 100 days after tumorimplantation. Any animal found moribund or whose body weight droppedbelow 14 g was euthanized prior to study termination.

Parameters Evaluated: Number of 100-day survivors, median day of death,and the increase in lifespan based on median day of death and expressedas a percentage (% ILS), median survival time and the % ILS based onmedian survival time.

The vehicle-treated control group had a median day of death and a mediansurvival time of 10 days. All animals died or were euthanized due tomoribundity between days 9 and 11. The maximum loss in mean body eightwas 32% (7 g). Due to the dehydrating effect of treatment with S-(1),animals in groups 2, 3, 5, and 6 that received treatment with S-(1) at adosage of 20 or 12 mg/kg/dose were given 5% dextrose in lactatedRinger's solution to lessen the debilitating effects of the treatment.

Administration of the Ringer's solution was initiated when animal bodyweights dropped by greater than 10% and continued until the animalrecovered, died, or was euthanized.

Intravenous treatment with S-(1), administered at dosages of 20 and 12mg/kg/dose on a q4d×3 schedule, resulted in a 60% and 45% ILS,respectively, whether the calculation was based on day of death orsurvival time. The corresponding median days of death and the mediansurvival times were 16 and 14.5 days for the S-(1) dosages of 20 and 12mg/kg/dose, respectively. One death occurred on day 2 in the groupreceiving treatment with the dosage of 20 mg/kg/dose. This death mayhave been treatment-related or may have been a delayed effect of theanesthesia used at the time of the is tumor implant.

Treatment with temozolomide administered at a dosage of 80 mg/kg/dosegiven po q4d×3 was quite effective against the growth of the U251 CNStumor cells with an ILS of 380% when calculated based on median day ofdeath (48 days) and 400% when calculated based on median survival time(50 days). There was one survivor in this group at the time of studytermination on day 100. Treatment with temozolomide was toleratedwithout treatment-related deaths and with only a minimal loss (8%, 2 g)in mean body weight.

Administration of S-(1) given iv at a dosage of 20 mg/kg/dose incombination with temozolomide given po at a dosage of 80 mg/kg/doseresulted in an ILS of 575%, with the median day of death and the mediansurvival time both being 67.5 days. The maximum loss in mean body weightloss observed in this treatment group was 22% (5 g). The loss wasrecovered following cessation of treatment. One death occurred on day 5,two deaths occurred on day 9, and one death occurred on day 16, possiblyfrom toxicity of S-(1). The remaining six animals in the group didrespond to therapy with deaths occurring between days 64 and 90.

The group receiving treatment with S-(1) at a dosage of 12 mg/kg/dose incombination with temozolomide at 80 mg/kg/dose responded more favorablythan the group receiving the higher dosage of S-(1). The median day ofdeath was day 73, with an ILS of 630%, and the median survival time was75 days with an ILS of 650%. Results are shown in FIG. 3.

TABLE 4 Summary of U251 Orthotopic Intracranial Xenograft Study S-(1) 20mg/kg, ip. 60% ILS (survivors day 100 = 0) QD1, 5, 9 Group 2 Group 2 vs.2, P = 0.000 S-(1) 12 mg/kg, ip. 45% ILS (survivors day 100 = 0) QD1, 5,9 Group 3 Group 1 vs. 3 P = 0.000 TMZ 80 mg/kg, po. 380% ILS (survivorsday 100 = 1) QD1, 5, 9 Group 4 Group 2 vs 3, P = 0.450 TMZ 80 mg/kg,po. + S-(1) 575% ILS (survivors day 100 = 1 20 mg/ip. QD1, 5, 9 Group 5Group 4 vs 5, P = 0.683 TMZ 80 mg/kg, po. + S-(1) 650% ILS (survivorsday 100 = 3) 12 mg/kg ip. QD1, 5, 9 Group 6 Group 4 vs. 6, P = 0.046Group 5 vs. 6, P = 0.108

Monotherapy with temozolomide produced an excellent effect against theU251 human CNS tumor cells, while S-(1), administered alone, produced amoderate effect.

Combination treatment with S-(1) and temozolomide was quite effective atboth dosages of S-(1). The better response was seen in the combinationgroup receiving the lower S-(1) dosage, possibly because of toxicity ofS-(1) at the dosage of 20 mg/kg/dose.

Toxicology. Central Nervous System (CNS) safety study in rats:

The objective of this study was to evaluate the acute pharmacologicaleffects of S-(1) on the central nervous system following intravenousadministration in the male albino rat. This study was conducted atClinTrials BioResearch (CTBR, Montreal, Quebec, Canada) as a GLP study.

Results: All animals were observed twice daily for signs of ill healthor reaction to treatment, except on day of arrival and necropsy. AFunctional Observation Battery

(FOB) assessment, along with grip strength, hind limb splay and bodytemperature measurements were performed for all animals once pre-doseand at approximately 15 minutes, 1 hour, 4 hours, 8 hours and 24 hourspost-dose. After the last observation, all animals were euthanizedwithout further examination. There were no deaths or treatment-relatedclinical signs.

A single intravenous administration of S-(1) at 6.25, 12.5 or 25 mg/kghad no biological effect on central nervous system, when measured byqualitative assessment of the functional observational battery andquantitative assessment of grip strength, hind limb splay, and bodytemperature at approximately 15 minutes, 1, 4, 8 and 24 hours post-dose.

TABLE 5 Results of CNS Safety Study Dose Dose Dose No. of Group/ LevelConcentration Volume Animals Identification (mg/kg) (mg/kg) (mL/kg)Males 1 Control 0 0 3 8 2 S-(1) 6.25 2.08 3 8 3 S-(1) 12.5 4.17 3 8 4S-(1) 25 8.33 3 8

Dose levels of 6.25, 12.5 and 25 mg/kg had no biological effects on thecentral nervous system of male Sprague Dawley rats followingadministration by intravenous injection.

The no adverse effect level for this study is 25 mg/kg.

Clinical Studies of S-(1)

Two Phase 1 trials examining the safety and pharmacokinetics of multipleascending doses of single agent, intravenous S-(1), when administered intwo different treatment schedules, are ongoing. Both trials haveenrolled patients with advanced solid tumors, non-Hodgkin's lymphoma orHodgkin's lymphoma that have recurred or progressed following at leaststandard therapy; patients with malignancies for which there is nostandard therapy; patients who are not candidates for standard therapy;or patients who have chosen not to pursue standard therapy. In StudyS-(1)-O1, intravenous S-(1) is administered weekly for 3 consecutiveweeks followed by one week of no therapy;

treatment cycles are repeated every 28 days in patients who remaineligible for continued treatment. Study S-(1)-O1 is currently beingconducted in the United States. In Study S-(1)-02, intravenous S-(1) isadministered every 3 weeks; treatment cycles are repeated every 21 daysin patients who remain eligible for continued treatment. Study S-(I)-02is currently being conducted in the United States and in Israel.

TABLE 6 Clinical Studies of S-(1) Study No. Patients Enrolled Phase DoseGroup Protocol Regimen S-(1)-01 27 S-(1) i.v. in a 50% cremaphor, Phase1  7 mg/m²: 4 pts 50% ethanol formulation over 1  14 mg/m²: 4 pts houror less weekly × 3 fol-  28 mg/m²: 4 pts lowed by 1 week of no therapy 56 mg/m²: 4 pts (28-day treatment cycle) 127.5 mg/m²: 7 pts  185 mg/m²:4 pts S-(1)-02 20 S-(1) i.v. in a 15% cremphor, Phase 1  56 mg/m²: 2 pts85% ethanol formulation over 1  84 mg/m²: 1 pt hour or less every 3weeks 126 mg/m²: 3 pts (21-day treatment cycle) 185 mg/m²: 6 pts 160mg/m²: 8 ptsClinical Safety—Adverse Events:

Dose Limiting Toxicity: Dose limiting toxicity has been observed in onepatient in Study S-(1)-01 who received 185 mg/m² of S-(1). The doselimiting toxicity was Grade 3 sensory neuropathy. Dose limiting toxicityhas been observed in 2 patients in Study S-(1)-02 at a dose of 185mg/m². In both patients, the dose limiting toxicity was Grade 3 sensoryneuropathy.

Clinical Pharmacokinetics:

Pharmacokinetic data for the Phase 1 studies S-(1)-01 and S-(1)-02 aresummarized in Table 7. Plasma pharmacokinetics of S-(1) were assessedfollowing the first dose of S-(1) in both studies. Plasma samples wereanalyzed for S-(1) using a validated LC/MS-MS method. Two differentformulations of S-(1) were administered in the two different Phase 1studies: a 50:50 (w/v) formulation of Cremophor EL-P/ethanol,administered in the S-(1)-01 study, and a 15:85 (w/v) formulation ofCremophor EL-P/ethanol, administered in the S-(1)-02 study.

Analysis of the PK data revealed that the plasma AUC of S-(1) appearedto be relatively dose proportional, with a moderate level ofinterpatient variability. Plasma t_(1/2) values ranged from 3.45-8.4hours for the S-(1)-01 study, and from 3.43-8.96 for the S-(1)-02 study.Clearance did not appear to be dose-dependent in either study. There didnot appear to be any difference in pharmacokinetic parameters, includingV_(ss), for the two different formulations of S-(1).

TABLE 7 Plasma Pharmacokinetic Parameters for S-(1) Dose AUC₀₋₂₄ Cl Vsst_(1/2) (mg/m²) (ng/ml * hr) (L/hr/m²) (L/m²) (hr) Study S-(1)-01 (50:50Cremophor EL-P/ethanol formulation) 14 457 ± 297 35.5 ± 29.7 23.2 ± 74.5 8.4 ± 11.5 28 682 ± 322 43.5 ± 14.5 309 ± 161 3.45 ± 1.09 56 2070 ±888  28.6 ± 13.2 216 ± 70  5.66 ± 3.63 85 5970 ± 3900 16.6 ± 9.26  142 ±75.6 5.52 ± 5.26 127.5 4460 ± 2140 30.2 ± 11.9 239 ± 116 6.59 ± 2.60Study S-(1)-02 (15:85 Cremophor EL-P/ethanol formulation) 56 2530 ± 847 18.9 ± 9.53  232 ± 93.6 8.96 ± 7.09 84 3710 15.4 300 — 126 6110 ± 303022.1 ± 11.2 166 ± 105 6.27 ± 3.64 185 7260 ± 2620 24.7 ± 12.2 215 ± 1163.43 ± 7.31Summary of a Study of S-(1): Administered Weekly in Patients withAdvanced Cancer:

In preclinical studies, S-(1) demonstrated antitumor activity againstmultiple human tumor xenografts in nude mice, including xenografts thatexpressed mdr-1 and that were resistant to other taxanes. The safety andtolerability of S-(1) when administered weekly for 60 minutes for 3weeks followed by a 1 week rest (4 week cycle) was examined in thisPhase 1 dose escalation study in patients (pts) with advanced neoplasms.

Treatment cohorts consisted of 3 pts and were expanded to 6 pts in theface of dose-limiting toxicity (DLT); pts could remain on study untilthe development of progressive disease or an intolerable adverse event.DLT was defined as Gr 4 heme toxicity lasting 7 days; febrileneutropenia, Gr 3 thrombocytopenia with bleeding, Gr 3 elevation oftransaminases lasting 7 days or any other Gr 3/4 toxicity other thannausea or vomiting. Results: 25 pts (M:F 16:9, median age 60, range24-86) were enrolled in 7 dose levels ranging from 7-185 mg/m². Pts'cancers included colorectal (6 pts); NSCLC (2); prostate (2); squamouscell carcinoma (2) and 1 pt each with cervical, breast, ovarian,gastric, pancreatic, bladder endometrial, NSCLC, SCLC, glioblastoma,melanoma, renal cell and hepatocellular carcinoma. All pts but 1 hadreceived prior chemotherapy (median no. prior treatments: 3 (range,1-7). Drug related adverse events included nausea, vomiting, diarrhea,fatigue, anorexia, rash, anemia and peripheral neuropathy. DLT of Grade3 peripheral neuropathy has been observed. PK data to date reveal thatAUC is generally dose linear. At a dose of 127.5 mg/m², clearance was30.2+11.9 L/hr/m² and tm 8.6+1.3 hrs. Anti-neoplastic activity was seenin a patient with pancreatic cancer.

In conclusion, S-(1) can be safely administered in doses of up to 185mg/m² weekly×3 in heavily pre-treated patients. It is predicted that inchemo-naïve patients, or patients with more limited exposure tochemotherapy, that the dose could be escalated even further. S-(1) hasactivity in pancreatic cancer. PK is dose linear and predictable.

Summary of a Phase 1 Study of S-(1): Administered Every 21 Days inPatients with Advanced Cancer:

In preclinical studies, S-(1) suppressed the growth of multiple humantumor xenografts in nude mice, including xenografts that expressed mdr-1and that were resistant to other taxanes. The safety and tolerability ofS-(1) when administered every 21 days was examined in this Phase 1 doseescalation study in patients (pts) with advanced neoplasms.

S-(1) was administered over 1 hour every 21 days in ascending doses togroups of 3 pts. Treatment cohorts were expanded to 6 pts in the face ofdose-limiting toxicity (DLT); pts could remain on study until thedevelopment of progressive disease or an intolerable adverse event. DLTwas defined as Gr 4 heme toxicity lasting 7 days; febrile neutropenia,Gr 3 thrombocytopenia with bleeding, Gr 3 elevation of transaminaseslasting 7 days or any other Gr ¾ toxicity other than nausea or vomiting.

Results: 14 patients (M:F 5:9, median age 58.5, range 49-77) wereenrolled in 5 dose levels ranging from 56-185 mg/m². Patients' cancersincluded colorectal (5 pts), esophageal (2), pancreatic (2), NSCLC (2),breast (2) and ovarian (1). All patients had received prior chemotherapy(median no. prior treatments: 3 (range, 2-10)). Drug related adverseevents included mucositis, vomiting, diarrhea, neutropenia,thrombocytopenia, myalgias and peripheral neuropathy. Only 1 pt.experienced Gr 4 neutropenia. DLT of Gr 3 peripheral sensory neuropathywas observed at a dose of 185 mg/m². At a dose of 160 mg/m² no DLT wasobserved. 1 pt with pancreatic cancer had a confirmed response to S-(1).PK data reveal that AUC is generally dose linear. At a dose of 126mg/m², clearance was 24.7±12.2 L/hr/m² and t_(1/2) was 10.6+7.1 hrs. Itwas determined that S-(1) can be safely administered in a dose of 160mg/m² every 21 days in heavily pre-treated patients. It is predictedthat in chemo-naïve patients, that the dose could be escalated evenfurther. The dose limiting toxicity was Gr 3 peripheral neuropathy.S-(1) appears to have activity in pancreatic cancer. PK is dose linearand predictable.

Oral Dosing of the Compound of Formula S-(1):

The compound of Formula S-(1) when dosed either oral or iv showsefficacy in mouse xenografts. From these efficacy studies and MTDstudies, the “apparent oral bioavailability” of the compound of FormulaS-(1) in nude mice would be in the 70 to 80% range.

TABLE 8 The compound of Formula S-(1) Injection Mouse PK Parameters IV10/mg/kg C_(max) (nM) na t_(max) (hr) na t½ (hr) 6.1 AUC_(last) (nM ·hr) 6298 AUC_(inf) (nM · hr) 7738 CL (L/hr/kg) 1.49 Vdss (L/kg) 13.35S-(1) - Oral 10 mg/kg C_(max) (nM) 460 t_(max) (hr) 6.0 t½ (hr) 5.1AUC_(last) (nM · hr) 3434 AUC_(inf) (nM · hr) 3609 F (%) 47Efficacy of Orally Dosed S-(1) in Mouse Neuroblastoma Xenografts:

Summary of Experimental Protocol: Human neuroblastoma tumor cells wereimplanted via subcutaneous injection of 1-10×10⁶ cells in nude mice.Tumors were allowed to grow to 200 mg+/−50 mg in size. Drug dosing wasinitiated, and tumor volume and body weight were recorded twice weekly.

Data Analysis:

The mean value for % body weight change and % tumor volume increase foreach experimental group was plotted including error bars for thestandard error of the mean.

Other metrics for assessing antitumor effects include: % T/C values ascalculated by the following formula:

$\frac{\%\mspace{14mu}{Mean}\mspace{14mu}{Tumor}\mspace{14mu}{Volume}\mspace{14mu}{of}\mspace{14mu}{Treated}\mspace{14mu}{Group}}{\%\mspace{14mu}{Mean}\mspace{14mu}{Tumor}\mspace{14mu}{Volume}\mspace{14mu}{of}\mspace{14mu}{Control}\mspace{14mu}{Group}}$Log Kill=(T−C)/3.32×(Td)

T is the time in days for the median tumor volume to reach 1 gram intreated group

C is the time in days for the median tumor volume to reach 1 gram incontrol group

Td is the tumor doubling time in days

Cures are excluded from T-C calculations

Results are shown in FIGS. 4 to 9.

S-(1) Rat Oral Bioavailability:

IV formulation (Cremophor El P/alcohol) and a suspension of the compoundof Formula S-(1) in aqueous medium: Several studies were performed toinvestigate specific parameters. It was found that there is a genderdifference but it does not influence bioavailability (F) overall, theformulation dilution does not impact F, there is saturation of theabsorption that seems formulation dependent, and the data isreproducible between experiments. Further, there is no significantdifference in F with different formulations.

From the solubility and compatibility studies between the compound ofFormula S-(1) and excipients that could be used, a reasonable list offormulations were evaluated in vivo:

TABLE 9 AUC last AUCinf/Dose (hr * (hr * kg * ng/ml) ng/mL/mg)Cremophor:EtOH 50:50/dil. 1:9 2220 426 Tween 80:EtOH:Labrafil:Labrasol5740 427 25:25:35:35/dil. 1:1 Solutol:EtOH 60:40/dil. 1:1 6590 503 VitE-TPGS:Cre:EtOH:D5W 1450 266 50:17:17:16/dil. 1:3 Solutol:Cre:EtOH:D5W2370 431 50:17:17:16/dil. 1:3 Lutrol:Cre:EtOH:D5W 2380 43640:20:20:20/dil. 1:3 Oleic Acid:Cre:Captex:Capmul:D5W 2610 5558:25:33:17:17/dil. 1:3 Solutol:EtOH:Labrafil:labrasol 50:10:25:15/dil.1:1 Gelucire:Labrafil:PEG300 60:20:20/dil. 1:1

Using the 50:50 CremophoπEthanol formulation as a case study (AUC last:2540; norm AUCinf: 477), F was calculated from the ratio of thenormalized PO and IV AUCs: F(%)=norm. AUC PO/norm. AUC IV.

TABLE 10 AUC last AUCinf/Dose Calculated (hr * ng/ml) (hr * kg *ng/mL/mg) F (%) Cremophor:EtoH 50:50/ 14600 2040 ~23% dil. 1:9 dosed IVCremophor:EtoH 15:85/ 4470 970 ~49% dil. 1:9 dosed IV

Results: It was determined that the “calculated F” underestimates thereal bioavailability as there is an effective F close to 60-70% (using acremophor-free formulation as reference).

In conclusion, it was found that Cremophor is not absorbed through thegut as the compound of Formula S-(1) delivered orally from aCremophoπEtOH formulation is cremophor free in systemic circulation. Inaddition, in vitro studies show that a fraction of the S-(1) isomer isalso degraded over time in Simulated Gastric Fluid into a known compoundthat is not orally bioavailable. A limiting factor is that there isdegradation of S-(1) over time in acidic media (GF), 3 to 4% per hourthat limits the overall bioavailability. Overall, it was found thatS-(1) Injection (Cremophor+Ethanol) is an effective oral formulation forthe compound of Formula S-(1).

Accordingly, the invention comprises a polyethoxylated castor oilformulation comprising the compound of Formula S-(1). Preferably, thepolyethoxylated castor oil formulation comprises about 50% ethanol andabout 50% polyethoxylated castor oil or about 85% ethanol and about 15%polyethoxylated castor oil.

The invention claimed is:
 1. A compound of the structure of formula (1):


2. The compound of claim 1, wherein the compound of formula (1) is anisomer having the structure of formula R-(1):


3. The compound of claim 1, wherein the compound of formula (1) is anisomer having the structure of formula S-(1):


4. A pharmaceutical composition comprising the compound of claim 1 and apharmaceutically acceptable carrier.
 5. The pharmaceutical compositionof claim 4 further comprising one or more chemotherapeutic agentseffective in the treatment of brain cancer.
 6. The composition of claim4 which further comprises temozolomide or bevacizumab.
 7. Thecomposition of claim 4 formulated for oral administration.
 8. Thepharmaceutical composition of claim 4, wherein the compound has thestructure of formula S-(1):